I know that some (most) of these are ridiculous to hope for, but whatever.

• Spike Spiegel - Cowboy Bebop
• Sharon Apple (with red or orange hair, specifically) - Macross Plus (I actually thought I wouldn't even be able to find one of these for sale, but I did. Too bad I don't have $180 for it -__-)
• Lina Inverse (or anyone, really) - Slayers (preferably from one of the movies/OVAs or an episode where she is wearing a non-standard outfit)
• Mikako - Gokinjo Monogatari (yay, my first cel)
• Basically any Miyazaki cel
• Anything from Project A-ko - either the first or second movie.
• Anything from Magnetic Rose (preferably with the original background)
• Anything from GS Mikami
• Anything from Gunbuster
• Anything from Evangelion (probably Rei, Misato, or Kaji. Maybe Ritsuko too. But really anything would be awesome.)
• Mokona, Umi, Ascot, or a few other characters - Magic Knight Rayearth
• Kero, Suppie, Li blushing at Yukito, or a pretty Clow Card - Card Captor Sakura
• Card girl painting a Rose girl - Miyuki-chan in Wonderland (I know this is kind of an ecchi OVA but come on, CLAMP + Alice in Wonderland.)
• Paprika - Paprika (I feel like I heard this was partially cel animated, but even if it's all digital, it would be cool to at least get a genga or a douga)
• Anything from Di Gi Charat
• Cutie Honey and maybe Sister Jill - Cutie Honey (Even though I'm not much of a fan of the original show, it would be cool to have)
• Anything from Sailor Moon, except Chibi Moon or the Sailor Stars
• Anything from Robot Carnival
• Lupin, Jigen, and/or Goemon - Lupin III (I found a pretty good one for $30 that I might get)