Here is a good interview with Mark Hamill, who voices The Joker in Batman: Arkham Asylum and in the DC Universe animated cartoons. He talks about coming back for the videogame sequel and his thoughts on Heath Ledger's portrayal of The Joker in The Dark Knight. Click on the link to read the interview.
Mark Hamill Batman: Arkham Aslyum 2 Interview
Mark Hamill Batman: Arkham Aslyum 2 Interview