Hmm. My two favorites would have to be:

Kathleen's cel gallery: OP cel of Ryoko as Snow 
White surrounded by dwarves

Nick/Anime Chaos: 2nd TV (labeled "Tokyo-3")

I've pretty much lost interest in collecting 
Ryoko cels. This cel is in the same sequence as 
one of Nick's that I admired for a long time, but 
when she finally arrived I didn't even open the 
package until almost two weeks later. I'll 
probably be offering her to a more loving home 
some time in the future.