When I want to compare phone I generally use PHONE SCOOP to give me a pretty good overview and compare of the phones I'm interested in researching farther, I by no means only use this site for reference it's just the first site I start with
http://www.phonescoop.com/
When I find the phone with the features I'm looking for, I'll then check reviews usually at CNet or various other sites Google leads me to
Lastly, I'll check what people are saying about the phone in users forums, this is how I ended up finding PPCGeeks!