Of course, I'm late in joining the discussion...

But the first choice is easy -- they'll have to 
pry my Zelgadis cels out of my cold, dead 
fingers, so Slayers is #1

Jubei Chan would have to be second, because I 
have several cels from that series that I just 
adore.

Probably Fushigi Yuugi third, but it gets dicey 
trying to choose between that, Card Captor 
Sakura, and Inuyasha...  arrgh.