^I hope you will get the other seasons soon
The only season I don't have on DVD is S5 but I gotta say I liked it less than the other because a lot of the great main cast were missing and I actually haven't seen that season more than one or two times and it was a long time ago so I don't remember it well now, may be I will get the Dvds of it too some day.
But my fave seasons are S2 and S3
Those are so awesome and hilarious!
And it has the best cast
Although I have to say I have a special place for S4 too since there's Robert Downey Jr in it and I totally have a huge crush on him
lol And I love Larry Paul character too
Season 1 was good too, I always only randomly watch few episodes from every seasons but I might start to rewatch the show from the beginning again too