Stability is relative. Zach and I have discussed this before – he has a 14′ Old Town Guide and loves it; I had the same canoe for a long time and always thought it was squirrely.
If you don’t have to portage and you’re not fishing fast water where you need to be agile and maneuverable, I tend to think the best choice is the biggest, widest aluminum canoe you can get your hands on. You lose a little bit in paddling speed from the weight, but there is a tradeoff advantage because the wind won’t push you around nearly as much on breezy days.
My main canoe now is a 17 foot Alumacraft that is like a tank – but it’s as stable as a jon boat and a heck of lot easier, in my opinion, to fish out of than the Old Town Guide.
I wouldn’t recommend a big Alumacraft like that if you’re going to have to carry it far, or if you’re going down Class 3 water, but for fishing lakes and slow rivers, it’s the best paddling option I’ve found.
Edit: