I had the Belkin, but it was cheap and rubbery, and the case interfered with the power adapter. It also fit on top of the Smart Cover hinges, making the Smart Cover not removable anymore.
I got the Aviiq, which is very nice, but expensive, and a finger magnet in the back. I am returning it.
I just today got the Incase from Best Buy. It has two magnets in the back to give you two positions to setup your iPad with the Smart Cover on a table. It also hold the Smart Cover when you open it, so its not flapping around. The back feels very nice, doesn't seem to attract as many fingerprints.
I think I found a keeper!!! 😎