The Finger Lakes area is very diverse. Each lake has its own personality.
As a PP suggested, Canandaigua is one of the nicest of the 11 Lakes, but others are great as well.
I work at a marina on Canandaigua for a boat club. If you happen to get to Canandaigua on a weekday drop me a private message and I’d be happy to arrange a 1/2 day tour of the lake on one of our boats.