43 Folders
Entertaining and practical advice on the business of doing the work that matters to you. The author offers many inspiring ideas -- along with the occasional friendly kick in the butt to remind you to go out and actually use them.

Eye of Argon MST (NSFW)
The story by itself is amusingly bad. With added commentary by Adam Cadre, it's hilarious.

Issendai's Lair
Humor lists and general silliness abound. This is a fun place to spend an afternoon.

The Legendary Lily Pad
Best. Flash movies. Ever. If you haven't yet been there, go now. Now, I say!

Movies in Fifteen Minutes
Wonderful parodies that neatly summarize dozens of popular movies. Interestingly, regardless of whether you loved or hated actually watching a movie, reading the m15m version is always great fun.

The Seventh Sanctum
Random generators and other creative tools for writers, gamers, and artists. No writer's/artist's block can survive a visit to this fun site.

TV Tropes
A comprehensive and witty guide to plot devices and conventions in TV shows, anime, and video games. Good times for fans and writers alike. (Warning: You may find it difficult to stop reading.)

Warehouse 23 Basement
There are some things man was not meant to behold. Those things are pretty awesome. Find them here!

What's Next?
One of many GTD applications. This is the best one I've found for getting stuff out of your head and into a place where it can be managed. It's free, fast, and just plain fun to use. (Look out for the productivity ninja in the user guide!)