The first 6-7 seasons were comedy gold. After Michael Scott was written off, it seemed like the show started to jump the shark. The show is still pretty funny, but the storylines started getting ridiculous. In the first 24 episodes after Michael left, we've seen 6 different branch managers!! There was Deangelo, Dwight, Creed, Robert California, Andy, and Nellie (and presumably Andy again).
The driving force of the show has always been Jim and Pam's relationship. In the early seasons, it was will Jim and Pam get together? Then it was will Jim and Pam get married? Then it was will Jim and Pam have a baby? Then they had a SECOND baby. Now, entering season 9... it seems as though Jim and Pam have gone as far as they can go story wise. You could tell Jim and Pam went as far as they could go, because even in season 8 the focus started to shift away from them and more towards Andy and Erin's relationship. Hopefully, whenever the show ends they tie up all the loose ends by bringing back Michael Scott maybe in the series finale to buy Dunder Mifflin and end the show with him as owner. Either way it's going to be sad when this show ends. People rag on The Office saying it sucks now, but honestly they've done a much better job since Michael Scott left then That '70s show did when Eric Forman was written off.