Return of the Joker
I've been stoking my Bruce Timm obsession by watching DVDs of the Justice League and Batman and the like while I work (using my peripherals!). I have to say it again, these cartoons are by far my favorite versions of the DCU. I also picked up the Gotham Knight DVD, and while greatly impressed with the animation, I wasn't as impressed with the overly serious writing. And if you're looking for sync winks, the Justice League cartoons will certainly keep you busy.
As will this cartoon, Return of the Joker. I'm not going to spoil the twist ending here, but I think anyone working on the Heath Ledger/Joker phenomenon might do well to pick this one up. And I must say that I am amazed at how compelling these cartoons all were, seeing how they were ostensibly written for children. It goes to show that good storytelling doesn't always need cursing and maiming and gun-totin' trannie whores to entertain and enlighten. Take a look at this clip and tell me it doesn't get under your skin. Let me add that this version of the death of the Joker is an alternate version. Both are very much worth taking a look at.
UPDATE: Droidy found this clip, syncing up the Joker and the Heavenly Beam. Special guest appearance by Anubis as Batman Beyond's (22) protector. It's a Semiotic Stew!