1. Marvel vs. Capcom / X-Men vs. Street Fighter - Always fun playing these games, whether it's in the arcades or on consoles. I'm also a huge X-Men and Marvel fan, so it's cool seeing my favorite characters alive in video games.
2. Mortal Kombat - The original on the SNES was the first fighting game I really got hooked on, and it got better and better from there
3. Street Fighter II
4. Killer Instinct