Hard to choose. Today, it would be Fatal Fury 4. Tomorrow, maybe Real Bout 3. Just for the feeling of the games.
I don't have any desire at all to see a MotW2, although that would be the most likely of the three, I think. One plane, 4 buttons, simple Street Fighter-style super moves that are easy to cancel into. More accessible to mainsteam gamers and Capcom fans. Parrying has become second nature to a lot of people, so I don't think Just Defend would alienate anyone. But the game just isn't as interesting or fun to me, as the RB or FF games are.