http://espn.go.com/nba/hollinger/powerrankings
I like this better than Marc Stein because it uses some objective data, though some could argue Hollinger's method is subjective. So yeah take it a grain of salt.
ETA: According to this the Rockets and Bucks are pretty overrated. Grizzlies less so, but some. The Pelicans are fairly underrated, thus far.