Anime USA - This has to be my favorite convention even though it's small and not well known. I have been going to it since their first year. Check it out if you have a chance
Sess Cels - Really nice Shessy cels
Art-Toons - Small cel dealer but nice cels. First met them at Otakon.
Kamidake Sakura Cels - One of the first cel galleries I saw when I first started collecting. Good collection of Card Captor Sakura cels
