I second the Wonder Boys rec - I love that movie. Other movies that come to mind are Barton Fink (yay Cohen bros) and I Capture the Castle, which isn't great, but which has its moments (most of which are thanks to Bill Nighy). Topsy Turvy is often dull, but the production design is gorgeous, and the cast is impressive.
Oh, and The Squid and the Whale was great, although like I Capture the Castle, it's more about the children of writers. There's also Kicking and Screaming, by the same author/directof of The Squid and the Whale (who also co-wrote The Life Aquatic With Steve Zizzou).