I did well with Orbitz.com, liked the motel and the rate.
I also lucked out with Hotwire.com, but only because someone else booked there before me and told me about their great deal. A big negative with hotwire is that they don't tell you the name of the place you're booking until after the booking is finalized! One downside to hotwire was that I paid for their extended coverage and when I wanted to leave one day early, they would not refund me for that extra night. Who knows WHAT that extra coverage was for....it certainly wasn't for cancelling one extra night!
One site I haven't used that seemed to list the same places as other sites, but at a few dollars less per night was motelplanet.com
I don't recommend the sites that instead of listing the price for each place, you have to click on a separate link for each and every place! (Yeah, RIGHT!!) An example of this is travelhero.com, so I don't recommend them.
Who have you booked with that you recommend? And which service will you never use again?
ETA: OOPS! I forgot expedia in my poll!
Other sites that didn't make the poll: