Farmington is conveniently located near several towns with great restaurants:
Farmington: Piccolo Arrancio (Italian); Wood-n-tap (casual, burgers, etc...)
West Hartford Center : there are several excellent restaurants in this area; to name a few:
Mediza (Mediterranean), Simmer Grille (upscale comfort food); Max's Oyster Bar (seafood); Harry's Pizza (as the above poster described!);
Plainville: J. Timothy's (best wings in the area, good beer selection); The Cottage
Hartford: Agave (Mexican); Mayor Mike's (American - nice hangout); Trumbull Kitchen (eclectic appetizers, casual atmosphere, a good martini); Black Eyed Sally's (barbeque; great music)
I hope this helps!!
You should definitely post on the New England board (and do searches if not enough comes up) to get more recs. I grew up in that area and live in NYC now but still visit quite a bit (and I'm assuming you will have a car):
Harry's Pizza in West Hartford Center - incredible thin crust pizza, even with all the great pizza here in NYC, I still wish I could have Harry's more often.
Amici Grill in Avon - Italian, in a boring looking strip of stores but don't let that deter you; the food is well prepared - especially the chicken marsala
Binn 228 on Ann St in downtown Hartford - great panini, salads and terrific wine list
Trumbull Kitchen in downtown Hartford - It's modern American with a few Asian or Latin American touches thrown in. I think you'll get a lot of recs for this place but I find it to be uneven. They mostly have small plates but do have entree options.
I think there is more than one Marriot in Farmington - is this the one near West Farms Mall and the United Technologies campus?
I second the recommendation to look on New England - we had a great meal at China Pan near the West Farms Mall in December - my bro in law followed up with a couple more. they even have dim sum and I could see camping out (or taking out from there for a while)
Be sure to ask for their Special Menu!