I'm not that great in fighting games but some that I enjoy mostly are:
MarvevsCapcom2(Arcade) - Still popular and played a lot at the arcades around here. This is one I enjoy the most because of its diverse set of 2 well known companies. It doesnt take much time to learn basics and link combos for some great fun. I have my wins and losses in the arcades myself but i am learning.
// MarvelvsCapcom 3 is awesome too!
SSFIV(360)- I am definitely liking this game a lot. <3 My favorites to play as are Fei Long, Sakura or Juri.
Darkstalkers!- I almost forgot, this was a weird one which is the reason why i like it. I didn't know this was the game Morrigan/Bulleta came from, and a few others in MvC2. My best character there is Bulleta.
(or B.B.Hood)
KingOfFighters(Arcades) - Not really a favorite but I have played a few times coming back from work and well, for me its a bit more complicated. I really enjoy watching skill people play, and i think once i get the hang of it i will be able to say more. ;P The only character i enjoy using is Kyo.
*SSB64<3