Pocket Fighter was the very first fighting game I ever played. It was super fun and I enjoyed it.
Generally not a fan of beat em up games, though, because they have generally gone like the following: I, not owning any beat em up games at all, am goaded into playing with a friend who knows all the buttons and moves and is a freaking genius and plays the game every night with their older siblings meanwhile I'm flopping around falling off platforms and dying or not doing any damage and ultimately end up with my ass handed to me in a 0-7 score or something. That's not fun.