A random person said:
I don't care how stylistically opposed they are, I want my Half Life 2 anime, damn it!
As for games based on anime, isn't Gurren Lagann begging for a game? Seriously, just watch it and tell me that kind of awesomeness isn't meant to be played.
Gurren Lagann apparently had a game already. And it apparently sucked. But it came with an OVA scene.
"Did you see it? Rabbit ears flaming and burning! Forced unification, USAGGON LAGANN!"
You can probably find the OVA on Youtube.
Anyway, for anime to game, I'd like to see a Nanoha RPG. Maybe even an MMO. Not necessarily with the characters themselves, but one where you could make your own character using the magic/technology classes from Nanoha. There actually is a Nanoha game being made by Namco (and thus, like most Namco games, probably staying in Japan) but its a fighting game. Bears a strong similarity to a fanmade fighting game crossover called Magical Battle Arena. I can't remember all the series involved, but Nanoha and Cardcaptor Sakura are in it.