I watched the original BBC (UK) Office a couple of years ago and REALLY liked it.
Bought it on DVD (and no, that's not an affiliate link) and have watched it over again countless times
I'm now caught up on "The Office US" as well, and I am impressed with how good it is. When I first heard they were making an American version I thought 'oh please.. not another remake / rip-off. Just air the BBC series on american tv for crying out loud...'.
I thought they would be unable to capture the mood and humor from the original, but thankfully - Ricky Gervais who played the boss in the UK series, and also produced it - is also behind the American one!
Steve Carell is perfect for the role as the US Office boss. But I'm telling you - for those of you who haven't seen the UK Office yet, do yourself a favour and SEE IT! It is truly hilarious.
Having seen both series and being a fan of both, here is my little quick review / comparison:
The Office US;
This version is sometimes more over the top than the UK one. In the US, the series sometimes have scenes or situations that would never actually happen or are a little too far fetched. Don't get me wrong though - it's all funny and good comedy, but it's sometimes more obvious that it is a comedy designed to make you laugh at extreme situations. The US series features most of the main characters from the UK series. And of course, all the characters are personalities most people can relate to from real life. I mean - we all know a Dwight (ultra-nerdy, annoying, obsessive compulsive perfectionist). Michael Scott, the boss, is of course the funniest character. Despite his flaws, he is a bit more liked by his employees than his UK counterpart David Brent. Where David Brent is just a pompous ass wanting to be liked, Michael Scott is kind of gullible (yet embarrassing) that some of the characters still like him for who he is.
The Office UK;
What makes the original so damn good is the acting by producer Ricky Gervais. As David Brent, he makes for such a believable bad boss that you just cringe in your seat at times. The UK series was also much more focused on trying to appear as a real documentary. When I first discovered the show, I was flipping through channels when I came across it by fluke. I actually believed I was watching a REAL office documentary! There was no laughter track (as is pretty common in 99% of all tv sitcoms) and it all seemed real. Until of course, David Brent started being a total asshat to people around him. Then I just started laughing. Because he makes you embarrassed for him and for the people around him!

To top it all, his brown-nosing nerdy companion, Gareth is also a perfect character in the UK show. I forget the actor's name (but I believe he also stars in the Pirates of the Carribean films). He is the UK counterpart of the American Dwight character. Full of nerdy 'wisdom' that no one wants to listen to (Military tactics, martial arts trivia, etc.). He is also constantly trying to kiss the boss' ass so he can get promoted.
In summary, the US version doesn't take the "documentary" feeling as serious as the UK one did. They make it more obvious that it is a comedy. It is still funny in it's own way though, and they still remake many of the scenes / situations straight out of the UK one.
But I still believe the original UK series is the best. Because all we saw there could actually happen in real life, and you can totally associate with all of it. It's utterly hilarious - yet painfully embarrassing to watch at times.
*semi-spoiler warning*
And for those of you who have watched the UK series, you also have to check out
The Extras (no aff. link)
It's another mini-series (6 episodes) made by Ricky Gervais AFTER The Office was made, but it is actually a prequel to the show! Very cleverly made. It also guest-stars Ben Stiller, Samuel Jackson, Patrick Stewart, Kate Winslet, and some others - playing (and making a parody of) themselves in a sometimes unflattering matter!
