All ports by capcom are good :) which means all console ports (apart from the sega master system port, which is impressive just not by capcom). The Amiga, spectrum etc etc ports were god awful.

Though apparently the super street fighter port on the Amiga is rather decent.

I'd love to read something in depth about the capcom console ports. The snes, magadrive and pc engine ports all look like some minor miracles! I remember an interview with a snes developer at rare were he said sf2 is the most impressive game on the snes. (Think I read that in retro gamer UK mag in the last decade or so).