I think most Marvel produced cartoons have been alright (the spin-off x-men and spiderman series evolution and spiderman unlimited weren't great, but about as bad as it gets)...
This one actually looks pretty good:
http://youtube.com/watch?v=-GbR_8-jWwQ
Looks set to follow the pivotal characters in the 3 x-men movies, but with alternate versions of events/continuity.
I'll be checking this out around fall...whenever that is...