It has some of the best news and rumors tidbits on the net. And you can meet a lot of nice people there. I met Nivelimac and Rando and DUke
at MTg news. And it was Yellowjacket who yanked me over here.
Of course, for posting and forum purposes, CPA has no rivals. MTGnews has some notoriety regarding spamming and nasty threads. They don't have as much regulation and monitoring over there.
But regardless, I consider MTGnews to be one of the best Magic sites on the net.