Man, I live in a canoe all sumer long, I have all kind... the one I use for hunting, is a Hellman Slocan, it is 17.5' and I use it solo but most of the time with my wife and daughter, We can fit a moose and 8 days of gear in it. It is a great canoe.
But there is so many brand to choose from, Do you do mainly lake paddling, or you do some mixe of lake, river and rivers with rapids? Do you need to cary a lot of gear for multy day trips?
If you do mainly lakes, I would suggest a 16 to 17' prospector in Kevlar, it will handle alsmost every thing other than class 2/3 rapids and be real light, can be paddle solo easily, and also can be portaged easily!
Let me know if you want more info.