What Makes A Dj... A Good Dj?

What makes a DJ... a good DJ?

the way they actually mix the music. instead of scratching all the time in some songs like limpbizkit - creamer (radio is dead). thats a little too much scratching. they also provide good sample's like bbe - limpbizkit. lethal does a really good sample there. also good works are mr. hahns work with cure for the itch and session. session got the best instrumental of 2003.

an unfathomable plethora of obscure, eclectic, esoteric sounds/samples/etc.

It completely depends on what type of music you are playing and the type of situation you are playing in.

banging out the rights tunes for the right time
properly mixing songs
being able to mix very different songs
just keeping people dancing most importantly