Stayed at the Sheraton Fallsview a few weeks ago and had a good view of the falls. Not only that, but got the room thru Priceline for (I believe) 45USD. We then paid an extra 20C$ to the hotel to upgrade the room to a fallsview room. Nice hotel, friendly staff.
Might be worth checking out Sheryl's Priceline & Expedia board (http://pub4.ezboard.com/bpricelineandexpediabidding) if you want to try for it...