It's more like what have I not started XD
I'm currently watching...
Hellsing Ultimate
and...
Rosario+Vampire
But I have a bunch more that I need to start soon.
If you want something good, check out Future Diary. I think the whole series is on Hulu for free and I'm sure you can find other places that have it too. It's insanely good.
Believe it or not, I've actually decided to re-watch Yu-Gi-Oh because I've been watching the insanely hilarious abridged...