I'm thinking about going this year, since I have more vacation time than I expected (due to foul-ups getting my vacation time for Otakon), and I have...
-Ban, default outfit
-Ban, Card Arc outfit
-Ban, Get Back the Missing Time outfit
-Emishi, default outfit
-Emishi, Venus de Milo arc outfit
Given the characters already listed above, and the fact that there are always Bans and Ginjis running around, sounds like Masaki's my best bet for maximum cast memberage if I do wind up going. Plus, if there's Kazuki and MakubeX and Shido... all four Kings.
"If people are going to laugh anyway, I want to try to make people laugh, and then laugh myself."
-Emishi Haruki, Get Backers