The purpose of the list is to request characters that you really want to see. Not characters that you think might be nice to have. Not characters that might sorta be fun to poke around with. No, it's for characters that you've been dying to play with, that you really, really want to interact with -- lovers, best friends, sworn enemies, etc. Things like that. Not just "character from the same series that would be good to have", because, you know, those will come naturally.
And, think about it this way -- if you request everyone, you won't get to see the ones you really want to see anyway.
When requesting, please comment with the character(s)'s name(s) and series(es), and a short paragraph (short; just a few sentences) saying why you'd like that character specifically. Requests without explanations will not be counted. (This is a good example for Sanaki and a minimum example for Tibarn).
You may second other people's requests (and keep them on the list if their motivation should disappear, be it a drop or otherwise) without a required explanation, unless your reasoning is extremely different. For example, say Tim-mun requests Joe because "He interacts so well with Tim and Maria!" and Maria-mun seconds this. Then if Tim-mun drops Tim, we'd still keep up the Joe request, until Maria is also dropped. However, if Maria-mun specifies that she's seconding Joe because "I think it'd be great to see him have an AU relationship with Roxanne," then the Joe request will be kept up as long as Maria-mun and Roxanne are still at Memento Eden.
Code Geass: Lelouch of the Rebellion
Lelouch vi Britannia
Crest/Banner of the Stars
Dragon Ball Z
Illyasviel von Einzbern (Heaven's Feel)
Rin Tohsaka (Unlimited Blade Works)
Fire Emblem (Elibe)
Fire Emblem (Tellius)
Howl's Moving Castle
Horokeu "Horohoro" Usui
Johann Faust VIII
Tales of the Abyss
Tales of Symphonia
Tales of Vesperia
Nicholas D. Wolfwood