To me, the quality of fighters varies greatly by the players involved.
I used to think the DoA series was complete button mashing crap, but when I met players that could actually pull of the counters and recounters and recounters, it become amazing.
I remember hating SF II when it came out because I couldn't pull off the dragon punch. But when you learn how to do it, it becomes great fun.
But to answer the question on pure preference, Capcom vs. SNK. It was a blast.
edit - also Virtua Fighter 2. I was blown away by the water stage and still have extremely fond memories of the Jacky vs. Sarah only stage. Good times.