Some of these have already been mentioned, but...
Atari 2600 Pac Man, Double Dragon, and Donkey Kong.
NES had Double Dragon, TMNT Arcade, and Paperboy.
SMS Altered Beast
Genesis MK (all)
SNES SFII
Intellivision DK
Any version of Pit Fighter I've played, any version of Operation Wolf I've played...

But of course, this all comes down to preferences and memories. SFII SNES was a huge disappointment to me, but some just loved it, it got rave reviews, etc. But for the die-hard quarter-spenders, it wasn't even close.