Try
TravelAxe to find your best price. They search a dozen or so different sites for the best price.
Do not book on the site with the lowest price. Call the hotel you pick directly and tell them the best price you found. They will match it or beat it. This way if you need to cancel, there will likely not be a problem. Booking with the online site may buy you the room whether you stay there or not.
Good luck....
PS I use the above method for finding flights as well. Use Travelocity, Orbitz, etc, then book the flight on the desired airline's website. It usually saves me $5 or $10 and gets bonus miles. [img]/images/graemlins/wink.gif[/img]