Compbros
Man of Tomorrow
It's definitely the worst I've had. MK9 online is virtually unplayable for me, hopefully Injustice sees an improvement.
KoFXII and Vanilla Marvel (before patch) were the true definitions of unplayable. KoF was like playing underwater every match and Vanilla Marvel would try to match you up with someone, fail, then send you back to the main menu and you'd repeat it. Then when you finally did play a match it was a ton of lag.
Just check this article, it's literally what would happen in Vanilla Marvel: http://www.ign.com/articles/2011/02/18/marvel-vs-capcom-3-online-problems