I'm no expert, but I have a pianist friend from whom I've picked some knolwedge. First of all, what is your budget and what kind of piano are you interested in: Grand or Baby Grand?
I just ask my pianist friend and he said Bösendorfer and Petroff are the best two then Steinway (preferably Steiway Haus which is German instead of the American Steinway & Sons). About Yamaha well he said to me: "Would you buy a piano from somebody who makes motorcycles?"
lol, thanks anyway.. I think it all depends on the person who's using it anyway. If that person is very caring about his/her stuff, then its gonna be alright.