My main "go-to" herb is Italian parsley. I go through 1-2 bunches a week. Now that I've started making charmoula on a weekly basis, I'll probably increase it.
Other candidates include:
chives -- as a garnish, in omelettes, pesto
mint -- in desserts, in soda, for infused syrups, in ice cream or sorbet, with Thai food, lamb, in salads, in tisanes, tea
thyme -- with lamb, in tisanes, in stews, soups, infused in port
oregano -- with tomatoes, tomato sauces, vegetables, Greek salad, pizza
basil -- mostly in Italian cooking: insalata caprese, pesto, stufato di verdure, etc.
rosemary -- with lamb; in Italian cooking: pollo alla cacciatore, etc.; in infused syrups, roasted vegetables
sage -- with brown butter, in soups and stews; fried in olive oil till crisp, then crumbled over pasta, vegetables or used as a garnish in salads
cilantro -- in charmoula, in Indian and Mexican cooking
Some things that I occasionally come across are: sorrel, marjoram and tarragon.
Not all of these are available year-round (I buy primarily from farmers markets).
One thing I like to do as the year progresses is an herb salad.