We stayed at the Marriott Fallsview. Nice hotel, had a room overlooking the falls. My early riser son loved to just sit and look out at the falls in the morning, I would join him with my cup of coffee. It was a nice peaceful way to start the day. Every early evening we would see a rainbow over the falls.
Take the Maid of the Mist boat ride to the foot of the falls. We went to Marineland, not a whole lot there, but they had beluga whales and they allowed you to touch them which made it worth every penny in my book! There is a part of town that has haunted houses and Ripleys Believe It or Not, all that kind of stuff.
We really had a nice time there, my kids ask to go back.