It depends on how many cels from each show you 
have.  I know with my gallery, I find it a PITA 
to have them all in one gallery (especially the 
Sailor Moon series b/c there's so many).  
Breaking it down by character or type (with 
Sailor Moon there's the Inner Senshi, Outer 
Senshi, Villians), makes it easier to view the 
images in a shorter amount of time.  I like 
having no more than 10-ish cel images on a page.  
But that's just me.  I used to have them all on 
one page and it took me forever (even with a T-1 
connection).  Just my thoughts.