-kun is mostly used for boys, although it can be used for girls of a similar standing aswel.
-chan is a term of affection, parent to child, girl to girl, sweathearts. Also used for pets, think about P-chan in Ranma 1/2.
And isn't -sama for like royalty? Like ouji-sama means Prince? I might be mistaken, but atleast I thought it was something like that. And of course it's a term of highest respect, as has been said already. And for people with big egos, naturally. ^^
24-Jun-2004