Last year I stayed at the Hilton Fallsview, and paid extra for the actual fallsview side. It was OK, as I was up on a high floor. The room had an in-room whirlpool that was nice, as you could see the falls from the hottub.

The view of the falls was there, but it was not particularly close. Go up close to one of the overlooks for an unforgettable view of unthinkable amounts of water continuously cascading over the falls.