Because I didn't see a topic.
Some of my favorites:
The one that pretty much started the craze, Yugioh Abridged from LittleKuriboh. He also did a few episodes of another anime...
Naruto! (not the actual Naruto Abridged Series, a parody of that series)
TeamFourStar, who do the fabulous DragonBall Z Abridged.
Yu Yu Hakusho, from Lanipator, who is a part of TFS.
Lupin the Third Abridged, from KaiserNeko, who is also a part of TFS.
Anyone else know any good ones I didn't mention? I know there are dozens more (I've thrown my own hat into the Abridged ring, but my series sucks