I'm not actively searching, but I thought it'd be fun to put up a wishlist.

Cardcaptor Sakura
Tomoyo. I will consider any cel, so please send me a scan or a link. ^-^

Di Gi Charat
Puchiko looking cute

Fushigi Yuugi
Yui in her winter outfit or as seiryuu no miko (this is a wishlist afterall ^^)

Sailormoon
I'm really picky when it comes to SM cels. I usually look at characters I like: Minako, Sailor Venus, Sailor V, Michiru, Neptune, Pallapalla, Luna, Artemis and Diana and Sailor Iron Mouse.