Whatever you do, just don't buy the dump that I talked you all into looking at just outside of Baxter in September! I'm all one for sweat equity, but that place was a bit much! Like you (and they) all say, location, location, location!!! HAHA, LOL.
.Stinson lake, forest lake near Littleton were both suggested and I would 2nd those, Kezar lake, Ossipee lake but that is large. My sister lives in Easton near kinsman trailhead with a view out her window of kinsman and lots of good road biking and cannon is nearby, but not on a lake. Shelburne, Randolph are also nice areas. Lake umbagog I think would be way too far.