I picked up Batman: Arkham Asylum, and despite all of the rave reviews about it, I still am just not interested enough to stop playing Marvel vs. Capcom 3. Seriously, this is the most entertaining, frantic fighting game I have ever played, and I don't think I'll ever be able to play anything slower ever again. The new Mortal Kombat just looks clunky and dull compared to this game. Obviously, actual fighting game fanatics will be able to point out intricacies that I'm missing, but this game is just so hyperactive that I'm willing to overlook numerous other glaring flaws (complete lack of story mode, almost everything one-player being padding, online matches have frustrating amounts of lag, ragequitter hell not kicking in nearly fast enough, etc, etc)
Also, I love the character balance so far. Sentinel was the only obviously broken character, and he just had a massive health nerf, meaning all kinds of characters are viable right now! Tournaments have had such wild choices as She-Hulk, Spencer, and Haggar, characters that everyone scoffed at when they were announced. Awesome!