SSB is my favourite, but SF comes in a close second

-Mortal Kombat gets by on its shock value. I never felt it had balanced fighting mechanics.
-Virtua Fighter has bland and forgettable characters.
-Killer Instinct was all graphics and flash.
-Super Smash Bros. is too chaotic with four players, power-ups, giant hands, and such.
-Dead or Alive is okay. A bit bland and simplistic, though.
-Marvel vs. Capcom has serious balance issues.
-King of Fighters is a poor mans Street Fighter (along with 99% of SNK's fighters).

For me, it comes down to Soul Calibur, Tekken, and Street Fighter. And even though I'm having a hate/hate relationship with Capcom right now, Street Fighter takes it.

No Urban Champion? What the hell man?

/sarcasm

My vote goes to Smash Bros. Out of all fighters it's the one I've had the most fun with.

Street Fighter and Virtua Fighter are great as well.

I still think Smash should be in a sub genre or something, even though I love it. I put Tekken.

Smash bros. My example of a perfect franchise.

I can hardly consider Smash Bros comparable to the others but it's for sure my favourite. Apart from it I say the best are Tekken, Virtua Fighter and Soulcalibur. My favourite between them depends on my mood.

for me it's mortal Kombat all the way. I've played just about every mortal Kombat game since the first one. love the characters and the whole setting.

Super Freakin Smash Brothers....
and then soul caliber pre-soul caliber IV.

I love Smash Bros. and was a big fan of Killer Instinct, but have to go with Street Fighter. It's really balanced and the controls are excellent.

Mortal Kombat is not that good of a game at all.