I recently acquired a copy of Grimm RPG. Its a twisted fairytale setting. And uses its own Unique mechanic called Linear D6 (PDF). I have to say that I really, really like the mechanic, and can see a lot of potential for it outside of the setting.
In particular is about the only system I know of that represents teamwork as a game mechanic, by allowing the players to pool their dice together for one big roll, which stands a good chance of getting a higher result than any one of them could have achieved individually.
I'm thinking this would work quite well in a lot for Anime inspired games. Especially ones that have similarly aged protagonists and an emphasis on teamwork and combo attacks against more powerful single opponents. The magic system which requires casters to build up power over multiple turns would also fit right in to many Anime worlds (Picturing Goku building up to unleash an energy blast, didn't he once do this for 6 episodes in a row before having his effect fizzle out).
The handling of size difference in combat situations is also very nice and graceful. I haven't really considered weather its realistic or not (then again I don't really care that much). But it does lead to a nice game balance in a game that can include kids facing off against giants.
Finally we get to the setting its self. And here is where Grimm really shines. The twisted fairytale world created is absolutly brilliant and includes elements both comic and absolutly terrifying. The idea of having Humpty Dumpty (now cracked and slowly rotting) being the source of corruption in the land of fairy tales is simply inspired. Other characters are similarly twisted, from a sadistic Cinderella to a a mad tooth fairy that has decided that simply pulling teeth is more efficient then waiting for them to fall out.
Setting details carry right through to the naming of traits and talents on the character sheet. Where Cool replaces Charisma and Imagination replaces Intelligence. WHile other games might divide skills into physical and mental Grimm divides them into Playground and Study. And all of them being measured by a grade level between 1 and 12.
Currently I'm experimenting with running a campaign online using Google wave as my play area. But I can't give any more details here as the some of people I've invited to play know where to find this blog.