I don't think International Karate or Yie Ar Kung-Fu are really beat 'em ups, they're more 1 vs 1 fighting games, but Kung-Fu Master is definitely a beat 'em up if you're looking for a classic early to mid 80's example of the genre. My spouse's personal favorite is Golden Axe II on the Genesis. =)
Ok then, perhaps Fist II: The Legend Continues counts as a beat 'em up, or even Usagi Yojimbo. While I've played a couple of the 1990's stereotypical beat 'em ups, it never was a big genre for me.