I was skeptical when I heard they were making an American version of The Office, even more so when the pilot was the same as the UK pilot...but that was pretty much where the similarities stopped, and it came into its own as one of the funniest shows on television right now, and in alot of ways even above and beyond the hilarity of the UK version. While Steve Carell is no Ricky Gervais, I think the supporting characters are far better in the American version.
I've even grown to like Rainn Wilson's character alot more than Mackenzie Crook's, even though he was my favorite character on the UK version.