It would be a pity to go all the way to Siem Reap and stay in a chain hotel. There are so many other nicer independent hotels (ok no points) that are not only cheaper but more personable.
I stayed at the Shinta Mani hotel in REP when I was there 2 years ago. The hotel contributes directly to the local economy where they train and educate the locals. Your contribution also subsidises local families.
Ok - so don't bother with it, but at least have a read :
http://www.shintamani.com/
Then of course, there's the FCC :
http://www.fcccambodia.com/angkor/
BTW if you're going to the Wats - consider a local guide and do the opposite from the masses.
The general consensus is : Temple Mount for Sunrise, then Ta Phrom, then Elephant Wall, then lunch then Angkor Wat.
My friend and I skipped Temple Mount and went straight to Ta Phrom at 7am and we were literally the only ones there, then to early lunch, then Angkor Wat (just when everybody is leaving for lunch) and we were one of many 30 other people there as opposed to one of hundreds!