Oooooo...tough question. The Arcade pricing model lent itself so well to the Beat-Em-Up genre. It's like that gameplay style was specifically tailored to eat quarters. A lot of solid arcade beat-em-ups got produced.
I'm going to have to throw in another vote for Aliens Vs. Predator. Capcom was one of the very best companies at beat-em-ups. AvsP was a solid, colorful beat-em-up based on two of my very favorite movie franchises. The character animation was extremely smooth and detailed, some really appealing sprite work. It was also one of the best games ever released based on either Aliens or Predator at the time that it came out. (the SNES version of AvsP was far inferior by comparison, though still in the same genre)
Outside of an arcade context, the beat-em-up genre doesn't hold up nearly as well. There isn't as much tension when you take away the quarter-munching, and co-op was one of the biggest strengths of those games. Playing a game like that solo with unlimited lives takes away a lot of the appeal. A modern re-interpretation of the genre would benefit from stronger multi-player co-op focus, as well as better incentivizing good play. If you are going to have a game with unlimited lives and continues, you need to give people a reason to avoid dying. And if you take away those lives and continues, you make the game too hard for casual players. (ie, wusses)