I like to control where I'm satying a little more than Priceline allows, so I go to Tripadvisor.com and have them compare rates on several sites (Expedia, Travelocity, Hotels.com) for various places. I also like that there are reviews of the hotels right there for you to read. Hotelkingdom.com has also been known to have great deals.
Make sure that you check and understand the cancellation policy of whatever site you use. Some will allow you to cancel within 24 hours of making the ressie without a penalty. Some charge a fee to cancel. And Priceline has a no-cancellation policy - you pay for it all upfront and lose it all if you have to cancel.
Once you find a great rate at the hotel of your choice, check the hotel's website to see if they have any specials that will match or beat the price. You can also call the hotel directly and ask if they will match the online price. The advantages would be that you control your ressie, you do not have to pay the full amount upfront (unless the hotel requires it) and you are subject to the hotel's cancellation policy (which is often more lenient). Good luck!