We (I) just put 1200 sf of prefinished 3/4" x 3.5" Maple (and 400 SF of Acacia in the bedroom) in our house. I chose prefinished because then I could do the entire project myself. (If you are somewhat handy and are a little brave, installing wood flooring is actually really easy - you can rent the tools at Home Depot) We bought it from Lumber Liquidators and they negotiated quite a bit on the price. We figured we paid about the same price as bare wood, but had a great factory finish on it too.
It doesn't end there with the prefinished though, because you always can (and some day probably will) have the floor redone. In my mind I basically saved the $2/SF for the first finish, and when I have it refinished in 10 years or so I will have it sanded smooth).
We have 2 Australian Shepards and although the floor is holding up really well, I at times wish we had went with a Laminate. My parents we with a laminate in their summer place. It ended up being a lot more expensive than the real wood we went with, but it hasn't even scratched yet AND looks really impressive.
Anyway good luck and have fun with it!