So I'm going to share the pain, and recommend some to you.
"Seeing the Sights," by Brian Doyle. Batman/Vertigo crossover. A horror/detective story, Batman versus the Corinthian. It's been a while since I've read this, but I still remember bits of it. There's a lot of good stuff here -- Doyle writes a very good Batman, and his Gordon and Robin are excellent, too. He's still updating, just veeeerrrry slooowly.
"In Brightest Day," by Kerithwyn Jade. Five words: Barbara Gordon as Green Lantern. One more: *Dude.* I love this story for the concept alone. Three parts, and I want more.
"The Substitute," by Anna. Harry Potter/The Crocodile Hunter crossover. Stop looking at me like that. Hagrid gets married, and decides to go back to just being gamekeeper. Leaving Hogwarts in need of a new Care of Magical Creatures professor, and well... DumbledorehiresSteveIrwin. The scariest part: he fits in. Really well. Yeah, it's just schtick, but it's really funny schtick, at least until the author kind of runs out of ideas around part five and starts writing a different story altogether. Actually, I don't mind that this one's unfinished. It gave me some laughs; that's good enough.