Behemoth:
First of all...enjoy your trip. Korean food is great stuff, with a tremendous variety not easily found in overseas Korean restaurants.
I'll make a number of suggestions below, but please understand that many Korean restaurants don't have particularly distinctive names and the best food is found on "this corner" or in "that little place, whatever its name is". As such, I'll present a number of options without names or useful directions. Let me know which ones particularly appeal and I will follow up to get you some more concrete directions for those.
jschyun has already given you the best general advice, which is to find a young, English speaking Korean to be your guide. Depending on whether you want to go for more traditional, "difficult" food or not, this may also be a hindrance, though. Traditional foodways are dying out among many young Koreans. I found myself introducing Korean friends of mine to traditional foods they had never eaten before.
Finally, I lived and worked on the north side of the river (
Kangbok), so many of my recommendations will be concentrated there. If you let me know where you will be staying, I may be able to target your area more.
On to the food!
- good street food to watch out for, stands if you know any good ones
Good street food exists in Korea, but it is much less a part of the culture than it is in southeast Asia. The one thing that I would suggest you
must try from the street is
deokbokki, a saute/simmer of rice cakes with a chili flake and paste based sauce, along with green onion, oden, and other ingredients. There are as many recipes for this dish as there are cooks. See
this thread for a discussion of
deokbokki. There is a great street stand selling
deokbokki,
twi gim (Korean-style tempura), oden, dumplings, and
sundae (Korean sausage) that is right near the Kolon Building in Gwanghwamun. The other things are good, but the deokbokki there is especially so. Then again, you can find these foods, along with ramen, simple stir fries,
kimbap (low-end, picnic food sushi rolls) and similar
bunshik at cheap prices in small shops all over Seoul.
- good bbq place, to take colleague who might not be the adventurous sort.
For upscale barbecue, I would make two recommendations. On the north side of the river, I think Jeil Garden (near the above-referenced street stall) does a good job. On the south side of the river, there is a place I'll have to look up directions for. It is more expensive, but also better.
If you do upscale bbq, you'll have a lot of meat choices. The most popular is probably
saeng kalbi, which is fresh, unmarinated beef ribs. Along with this, I would try
ggot dung shim, literally "flower sirloin". It is my favorite. Also available and liked by many is
an shim (tenderloin). I am not as fond of it for Korean
sut bul cooking.
One of the highlights of upscale bbq is all the
ban chan (side dishes). You'll be presented with many, but I think the best is
ge jang (raw crab partially "cooked" by its marinade). There are two varieties, both good. One is soy sauce based and the other is red pepper based. You are more likely to encounter the latter.
You will also have an opportunity to try one of the great cold foods after dinner. Typically, in one of those places, you will be offered a noodle/rice choice after dinner. The choices will vary, but
bi bim naeng myeon will usually be one of them. This is a dish of cold noodles with a pretty spicy pepper based sauce. I love it. Another common alternative after dinner is
doen jang jji gae (bean paste stew). You must try the latter at some point during your visit. Fortunately, it is available somewhere on every city block in Seoul.
There are other bbq options as well. It's a debatable point -- and the Koreans admittedly don't do anything with brains, kidneys, sweetbreads, lungs -- but one could argue that the Koreans are the masters of innards. Certainly, they do an amazing job with stomach and intestines. If these kinds of things interest you, let me know and I'll do a rundown on the different varieties and my favorite places to eat them.
Finally, you might want to go to a
sam gyeop sal place. These are cheaper and are great places to spend a long evening eating and drinking.
Sam gyeop sal literally means "three layer meat". It is also often referred to as Korean bacon. The best is actually
o gyeop sal (five layer meat). The layers refer to alternating fat and lean meat. There's a great
o gyeop sal place north of the river. South of the river, there's a trendy
sam gyeop sal place that specializes in meat marinated in wine, as well a bean powder dip. It is slightly more expensive, but, despite its trendiness, the food is very good.
- good place for dumplings
Good dumplings are all around. I would just stop and get them wherever they look good.
Bunshik restaurants will normally offer several varieties of dumpling. One thing you might enjoy is to go to a chain that offers three main things --
kal guk su (knife cut noodles in a clam broth),
wang mandu (king-sized steamed/boiled sumplings), and
to jong bossam (special pork, sliced and served with kimchee and condiments). I can't remember the name of this place, but there is one outside one of the Gwanghwamun metro entrances, next to the Sbarro or Pizza Bell or whatever it is.
- traditional korean restuatants in general, what should I try?
I have to admit that I am not nearly as much a fan of
"yangban" food as I am of everyday food. That being said, you probably should try it. I would go to one of these places and simply order a set course. It will come with many, many things. Two places I would recommend are: Yongsusan (for the food) and the restaurant in the base of Seoul Tower (for the views, though the food is pretty good too). The concierge at your hotel will be able to direct you to one of these. Yongsusan has branches on both sides of the river.
- very curious to try a traditional vegetarian restaurant
Unfortunately, I don't have a specific recommendation in Seoul. You would be well-served to take a trip out of town to Andong(?), where there are several great temples and accompanying vegetarian restaurants.
- would like to try summer specialities, cold dishes
I've mentioned
naengmyeon above. It also comes in milder varieties, such as
mul naengmyeon. You can find this many, many places and it will generally be good.
My favorite cold summer dish is "kong guk su", noodles with pureed beans. Simply phenomenal to me. I'll come up with a recommendation for a place if you are interested.
- maybe a decent non-fancy western place (eg italian, say) to placate travel companion if he start to rebel
I'll get criticized for saying this, but they don't exist. Korean food is some of the best food in the world. I would swim the ocean for it. However, there is hardly a western restaurant in Seoul that I would cross the street to eat at in almost any other city. It's a long, philosophical discussion as to why, but
this thread here (out of which I intentionally stayed) discusses it. There're plenty that one can enjoy, but there's just nothing to get excited about. And none of it is authentic, in the way that Italian or French places can be in Tokyo/Bangkok/Hong Kong/Singapore/etc.
Now, having said that, you still need somewhere to recharge or seek refuge. There are plenty of non-descript spaghetti restaurants around that will fit the bill. They're not really bad -- no worse than the comparable item in Tokyo -- but nothing to look forward to. Just walk through any crowded area with young people about and you'll find one. Just pick at random, as one's as good or bad as the next.
- a couple of good bars, student-y vibe sort of thing, nice but laid back
Can't really help you here, except to suggest a couple of neighorhoods -- Daehangro and Apgujang. The former is more studenty. The latter is more young and trendy. Just walk the neighborhoods and pop in to one or two.
- good places to get coffee, snacks while running around town
You will find both Korean and western coffee places absolutely everywhere. Korean style for coffee (
tabang coffee) is with lots of milk and sugar combined with instant coffee. Taken or what it is, it's not bad, but it's not really coffee either. Traditional coffee shops are called
tabang and used to be social centers for business meetings and such. The waitresses were often "available" as well. I don't know how much that is still the case, though I am told it is often still so near military bases.
American-style coffee places abound and are no different than the Starbucks in Anytown, US.
I would prefer snacks from the convenience stores or, better yet, a quick stop in a
bunshik restaurant. You'll pay a fortune to buy snacks from Starbucks or the Coffee Bean.
- I've heard there is good indian food to be had? I am curious about that also, but only if it is really different from what you'd get in a typical US place.
I eat a fair bit of Indian food, but am not an expert. I've never travelled in India, so I don't have the same reference point I do for many other Asian foods. That being said, I found Indian food to be the only foreign food in Seoul that was really well done. I would try a place called Dahl (near the Kyeongbok palace) or Ganga (locations in Seoul Finance Center and in Kangnam). They're expensive and not something you can't find in any good-sized city in the US, but they're good nonetheless. One warning though -- most Indian restaurants in Seoul (these included) typically use short-grain Korean rice. That, to me, is a major failing.
- good Sushi place worth seeking out?
My advice is to forget about sushi, but I mean that quite literally. Sashimi can be fantastic in Seoul. It's just the rice part that I've never seen work in Seoul. You might enjoy a trip to Noryangjin, the (much smaller) Seoul version of Tsukiji market. You can choose your live fish(es) out on the main market floor and have them cut by the vendor, then go to any number of adjacent restaurants who will charge you for
banchan, setup, drinks, while you eat what you bought from the market. At the end of the meal, they will make
maeun tang, a wonderfull spicy fish soup, from the carcass and innards. Don't let the vendor keep or throw away the remnants when he cuts you fish! You'll need it for the
maeun tang.
There are two other sashimi places I would suggest. First the expensive one -- a place called Badaui Gyohyangshi (literally "Symphony of the Sea", the name of a popular song from the 1970s or so) does an excellent job and, for a price, can provide special things like live giant crab and live lobster. There are tons of interesting things to try. I'm a bit of a fish nut and used to give tours of the market (to Koreans and foreigners) so let me know if you want suggestions for best/unique local seafood to try. I won't bore you with this if you don't ask.
I would definitely try a
chamchi place as well. These are tuna-only restaurants where you eat every part of the fish (from eyeballs to toro). A set meal is around $20-$25 exluding alcohol. I always gave out before the food did. It's not
honmaguro (normally either yellowfin or bigeye tuna), so it's not the pinnacle, but for the price it's damn good.
- Any good junk food to keep an eye out for?
See street stalls,
bunshik, etc. The triangle onigiri (
samgak kimbap) from the convenience stores are pretty good for a quick snack.
Recommendations about foods to try would also be very much appreciated. (Especially seasonal stuff, I am guessing it will be really hot & humid).
Don't get me started! Beware! A few quick thoughts, on which I'll expand if you are interested:
(1) It'll be dog season. If you decide to do it, I would suggest
toma gogi rather than boshintang to have it at its very best.
(2) A good, Korea-only experience would be to go to a Cheolla-do restaurant. Specialties include
saebal nakchi (small live octopus, literally "four leg octopus") and
hong eo (fermented skate -- challenging taste, with a strong ammonia smell but a great taste). Have these with
kkat kimchee (mustard plant kimchee) and
makkoli a spritzy rice beer. This is Korean soulfood at its best. One out of ten young people, if that many, eat these foods these days.
(3) If you encounter beef liver sashimi anywhere, definitely try it. I'd never had it before moving to Seoul and I wish I had found it much sooner in my time there. Here's
a thread that discusses liver sashimi in Japan and shows some pictures.
(4) It's not a summer food, but I think one of the world's great stews is
gamja tang, soup of potatoes, pork backbone meat and its broth, pepper (black and red), and
deul ggae (the seeds of the shiso/perilla/beefsteak plant).
(5) Perhap my single favorite Korean food of all time is
sun dubu jjigae, a stew of fresh, silken tofu in a peppery broth. Typically, it is served with rice and vegetables. The hot soup is spooned over the rice and vegetables and stirred in. My favorite versions all have a raw egg dropped into the soup at the last minute. My very favorite has fresh oysters in the broth as well. The ultimate version of
gul sundubu jjigae (oyster version) is from Woori Jib near Gwanghwamun. Unfortuntely, Woori Jib just means "Our House" or "Our Place" and there are a thousand restaurants with the same name.
I coul go on forever, but I will spare you. As soon as I hit send, I will think of ten more things I should have recommended. As you can see, I am passionate about Korean food and Korea. Please give me some indication what was interesting in my response and I will expand on those areas and suggest additional similar foods. I've just got to stop somewhere before I overload the board!
Hope this helps,
Jim
NB: Please forgive grammar, formatting, spelling. I want to get this off to you, but haven't had time to proof read. Something about the call of a six-day old child seems more compelling than proofreading, says the proud papa.