Give me a good ol' "DO ME, DO ME!" comment and I'll:
(1) Tell you why I friended you. (Disclaimer: I'll do my best to remember.)
(2) Associate you with something. A fandom, a song, a color, a piece of fruit. SOMETHING.
(3) Tell you something I like about you.
(4) Tell you a memory I have of you.
(5) Associate you with a character/pairing.
(6) Ask something I've always wanted to know about you.
(7) Tell you my favorite userpic of yours.
(8) In retort, you must spread this disease in your LJ (if you're so inclined.)