If you’re interested in collection airline points then you’ll want to check out PointsHound. It’s a site where you can book hotel stays and earn airline miles. Simple!
They have 150,000 hotels in their system and are partnered with about 10 airlines, including: US Air, American, Delta, Hawaiian, Etihad, Jet, Virgin America and a few others. And yes, they do have a lowest price guarantee.
I know I fly a lot more then I stay in hotels so this is a great way to get something usable out of those hotel stays.
When I first tried to use this for my trip to Australia I found all the prices were higher then my initial reservations were; however, they were the same as the prices I found on other sites. Although I didn’t get to use this for my own bookings, it is a site I will use regularly when trying to book hotel rooms.