The Riverside Farm Market Café, in Oakland ME is just a short drive from Waterville Maine Tpk Exit 127, and well worth the trip. A lovingly-run small business set alongside the Messalonskee river, they serve very good food in a friendly, casual manner. My wife and I were there for lunch the other day. I particularly enjoyed the quiche, a lunch staple that most restaurants make soggy and leaden. This was just about perfect. Same for wife's very-full lobster roll (could have used a bit more mayo) and the delicious pies. Wide-ranging and affordable wine list.
There's a tiny vineyard next to the patio dining area: they have not yet produced a satisfactory wine, but its presence adds a very charming touch to what's already a restful and attractive view.
The "Farm Market" is more of a gourmet store, with an impressive inventory of wines.
Well worth the short detour if you're in the Waterville (Colby College) area.