Well, the spinner has been my best bet so far, since I never get good items (red boxes) from quick matches or co-op. I've only drawn a red box a couple times, and both times, the match fell apart due to too few players.
And what the hell's up with so many little kids playing this game? and little kids who have no idea what the fuck they're doing on Xbox Live, at that. For the last couple days I've been getting party invites from some random twit I don't know; I finally give in and join the party, and it's some squeaking kid who sounds five years old (not exaggerating), saying "hola" and then some other stuff in Spanish.