Not surprising to see the large Smash bros community here.

Personally the best is Street Fighter. Love the serious level and skills used to pit against your opponent. Anybody that knows Evo would know why.

I also enjoyed DBZ Budokai 3, best DBZ fighting game btw. They just did everything so well to make it feel like the anime while playing.

The Naruto Ninja Storm series are by far the best anime transitioned-to-game ever created. They did what Budokai 3 did with DBZ....but next level better.

Smash Bros, easily. It's so hype to both play and watch.

it's always a bit awkward when a question like this is asked with traditional 2D fighters right next to Smash Bros, as one could consider the games quite different

traditionally speaking I would probably pick Killer Instinct, simply because it has a soft spot in my heart. buttttt obviously Smash Bros. as a series has went above and beyond anything else to make extremely intricate fighting circumstances with a wide variety of moves unique to each character, items, varying platforming levels, etc.

 Super Smash Bros. Melee is the gold standard for me, no fight in that game is ever the same and when you play it with more than 2 people it is somewhat addicting. I think what the Smash series also has done SO much better than any other fighting series, is provide stats and unique ways of play. If you play with a group you can play for a few hours and it will keep track of the number of KO's you have, victories, etc. all kinds of levels, tournament editions, a huge variety of weapons that you can specifically turn on/off (what other game has that! amazing feature). 

I'm rambling but beyond specficially the fighting category, I would argue that a game like Melee is one of the best of ANY category because it offers so much

I think you hit on a key thing- movement. so many of the traditional fighting games the players are sort of stucking staring at each other the whole time while fighting. the move combinations and freedom of jumping and upward attacks really allow a player in any Super Smash game to dramatically change the dynamic between them and their opponents (i.e. beyond just standing in front of one another seeing who can hit the best attack combinations more quickly)

I would say Super Smash Bros, but that game feels out of place when put next to these other fighters.  Feels like its own genre, even.  Tekken in that respect is the best 3D fighter I've had the pleasure to enjoy

I see Killer Instinct is disrespected. It's not fully done but what is has been near great. Use to be Dead or Alive now it's KI. The most fun I've had with a FG was the 1st Smash. Revolutionary to me. The icons fighting against each other and 4 players. No one could/can touch my Link.

Tekken is so far ahead of every other fighting franchise. Massive roster, unique fighting styles for each character, good balance, easy to learn, difficult to master.

For my money, Street Fighter II is still the all around best fighting game ever made. Not only has Capcom never truly topped themselves with that gem (outside of various iterations of it), but really neither has anyone else.

That isn't to say there aren't other great fighting franchises, King of Fighters, World Heroes, Samurai Shodown, Tekken, Virtua Fighter, etc.

1.Super Smash Bros
2.Street Fighter
3.Tekken
4.DBZ
5.One Piece