I would say that the best episode of The Office would be the Staff Training one. What's Your favourite? 
Best "The Office" Episode
The Staff Training one.
Everyone will say the one with the dance, won't they?
The Dinner Party.
The Soup Nazi.
Quote: Tim Azure @ February 13 2013, 5:36 PM GMTEveryone will say the one with the dance, won't they?
Oh yes I forgot about that one. It's a classic! 
First episode of Series 2.
Or the training one.
The Staff Training one I found clever and amusing but I thought it was a bit drawn out ie. not enough going on in 30 mins. The one with him playing his guitar?
So I'll say the Quiz Night one, verry funny. 'Frey Bentos'.
Quote: David Bussell @ February 13 2013, 5:44 PM GMTThe Dinner Party.
Actually yes, probably this one. Especially the vasectomy speech.
Quote: chipolata @ February 14 2013, 10:33 AM GMTActually yes, probably this one. Especially the vasectomy speech.
Carell, along with Ferrell are just about the two funniest people I can think of. What a shame the episodes with the pair of them in were so average.
OP nailed it imo:
All of the above. Plus the Christmas episode where Brent tells Finchy to f**k off.
(And thingy gives her the oil paints and a note to never give up. *weep*)
The Quiz Night one. Finchy is absolutely brilliant in it, the scene where we're introduced to him and he mocks Brent is superb writing and performing in a nutshell.