Not wanting to be stupid (ok.. losing battle) but what exactly are these huge expedia rewards? I've done quite a lot of travel and booking through them, and frankly, I am unsure what benefit I've got from it.
I like the Hotels.com rewards program. It's like a punch card, and you're not locked into a particular hotel chain. Stay 10 nights, get a credit for the average cost of those 10 nights. They also price match if you find a cheaper rate anywhere else.