Here are some ideas that I thought of for some possible sets
Viewtiful Joe -Plenty of heroes and villains from this series. Lots of options for duo and giant figures (Joe and Silvia, Fire Leo and Frost Tiger, Big John, King Blue etc..)
Heroes- I think it would be pretty cool to have a Hiro Nakamura with the kensei sword clix :D
Death note- Weird yes, but a clix of L or Light would be pretty sweet
A set based on the Marvel vs Capcom series - A great series loved by fans I think it could translate well to clix (since half of the series is marvel lol). Plus duo figures like Ryu and Wolverine and Dante and Deadpool would be awesome.

How in the world would you make a clix of Light? "As a minor action, KO any one figure on the board whose actual name is written on the base." I'd hate to be an old-school LE around him. : - )

Hanna Barbera.

Space Ghost, Johnny Quest, Herculoids....