Would the Sheraton you are talking about be the Sheraton Brock? It is close to the river but the Horseshoe Falls are not close enough for a good view. It's a very old hotel, historic even, but quite comfortable when I stayed at it 7 years ago. I can't comment on the Hilton.

Other things to do. Take the drive along the Niagara river to Niagara-on-the-Lake, a small , quaint town and a very scenic drive of about a half an hour each way. Do the Great Gorge Adventure. Scenic and fun. Look up Casino Niagara if you are willing to part with some excess cash. Bungie (sp) jump if you dare. Visit Marineland if you are bringing the family or just like being entertained by aquatic animals yourself.

Beware of all the museums on the main drag. Some are worth paying admittance to, such as Madame Tussand's or the Houdini "barrel over the falls" one, but most will leave you disappointed as they are just tourist grabs.

Take the time to visit the Welland Canal and watch how they lower the ocean going freighters in the locks. I've loved doing this since I was a kid.

Line up for the journey behind the Horseshoe Falls if you haven't already done this from the US side which takes you under the American Falls. See for miles from the top of the Minolta tower or the Skylon Tower where, at the latter, you can eat dinner while it revolves (food is okay, you pay for the view really). There is a cable car ride that takes you across the gorge; scenic but short. I think it's called the "something" aerocar.

Bring lots of your own film. The price of film in Niagara qualifies as highway robbery.

This isn't by any means all that there is to do but I tried to offer choices in various price ranges and for varied interests. Have fun and enjoy.