I guess it would either be Flathead Lake in Montana, or Lake Tahoe (Cal/Nev). Why? Well I've been to both of these lakes a number of times, but I've never paddled them. They are both fabulously beautiful bodies of water and at least when I've been there, they seem to have pretty stable conditions. I also like that there are no sea lions, no gators, no sharks, no orcas.... Hey, I don't paddle for adrenalin fixes and cheap thrills.
Which kayak? Hhhmmmm, oh I know--my NC Expedition. Bet no one could have guessed that.