I live in Oklahoma but travel to Dallas at least twice yearly to eat and shop. There are still lots of restaurants on my "to try " list, but of those I have tried my favorites are:
Abacus - get the tasting menu with the upgraded wine pairings
Sushi Sake - the salmon sashimi is amazing, uni sushi and grilled hamachi collar also very good
Meddlesome Moth - extensive beer selection; the mussels in coconut broth were delicious
Kalachandjis - great vegetarian lunch buffet, wonderful setting
Royal China - get handmade noodles and dumplings
Tei-An - can't remember what it is called but the pieces of Kobe cooked on a hot rock are TDF, expense account would be helpful
Mughlai - the best Indian lunch buffet I have ever had; if you go for dinner or don't like buffets get murgh malai kebab, kadhai paneer, or dal makhani; have a Kingfisher with your meal
Alounak - the lamb shish kabob was great and I would go back just to have it again, the falafel was not good
First Emperor Barbecue - get the green beans with pork and the scallion pancakes, this is the only place on my list that approaches "hole-in-the-wall"
If you have access to a kitchen or are driving and can shop for things to take home get lamb rib chops at Sara's Market.
Jimmy's is another great place to shop and the sandwiches from the deli are really good (try the tuna).