What site is the cheapest to buy Hotel tickets?

I need reservations by December 13th. I would like to buy it on line or even just reserve the room... what web site has the cheapest deals for a hotel room? Thanks!

I find that calling a travel agency usually knows all the best deals around rather than any of the services on the net. Too many hidden charges in things like travelocity and Cheap tickets. A good travel agency is usually up on good package deals.