My friend introduced me into 2D fighters recently for both the PS2 and xbox 360. At first, I was a bit skeptical, thinking "Oh man, this is gonna be a waste of time." But lo and behold, it was a blast. I felt like a little kid again button mashing in Mortal Kombat II. We both played King of Fighters XI (or was it 12?) on the PS2, and it was great. Button mashing and Super Special Leader moves were a win.
After a while, I decided to look more into 2D fighters and I came across BlazBlue. It's probably the most beautifully done 2D fighter I've ever seen. I bought the game, and went at it for weeks. The game is great because you feel like you actually can control the character. The game flows smoothly, the combos are sick (in a good way) and everything about the game is highly detailed. Online play, for the one month I had it, was also great. The skill matchup is pretty good too. You don't face too many people that you can spank or be spanked by. Don't even get me started on how great the music is as well. For anyone that has an Xbox 360 and is looking for a new game, get this game NOW!
UPDATE: it actually might be out for PS3 as well.
For High Quality video of a match, go here: http://www.youtube.com/watch?v=V2riCbWrrkE