Try Fancy Bagels. Right, you said "not fancy" but it's just the name. :) Great bagels, great sandwiches. There's one in Farmington and one in Southington. Their "Fancy BLT (with turkey)" was always a favorite.
Not having any idea what your preferences are and how far off the interstate you're willing to travel, a quick on and off at Queen Street in Southington would be Bertucci's. A little further north on Queen Street is Moe's Southwest Grille.