+1. I highly recommend OMMA for XBOX. I haven't swung by in quite a long time, so no clue how things have been lately, or how active things are nowadays, but I've always gotten along with K1LLA and used to compete there on XBOX. We even have a logo / link to the OMMA site on the EFC site, and vice versa;
http://www.efcleague.com/portal.