Alright... Lets try and figure this out - we already know UFC and Pride are the top dogs, so lets for for third place... 3 votes each... Ive done my best to include gifs.
Fighting Network RINGS:
Famous for launching the careers of many stars back in 2000-2001. And for this non-punch.
Pancrase:
Famous for having a very complicated and limit ruleset, which belied an extremely entertaining promotion. Lots of grappling. Famous for the Shamrocks, Bas, and producing this gif as a result of all the above:
Affliction:
As famous for the spectacukar shows it put on as for its spectacular Barnett-induced destruction. And for this punch.
Shark Fights:
Famous for having the GOAT conmentary team (Don Fry, Bas, and Quads), and giving old fighters a paycheque. No stand out highlights exist, but it was a good laugh.
DREAM:
Famous for having an honest attemptat taking over from where PrideFC left off, but falling way short. It was fun, and forgettable at the ssme time with mist if the big names treating it as a stepoing stone rather thana serious promotion. Also for this infamous momemt:
International Fight Legue (IFL):
Famous for finding a way to make fighting really complicated and having a lot of stars. also for this guillotine:
World Extreme CageFighting (WEC):
Famous for being the original stage for the smaller guys to fight on. And for this kick:
Bellator:
Famous for slowly rising up from nameless cans fighting on unpromited shows to hosting the legends of the sport at the end of their careers. Formerly seen as unfashionable, constantly gaining pace. And for this finish:
Strikeforce:
The former contender - a long history of awesome fights, big names, launched careers, and so much more. Scott Coker gave us something else to look forward to to when Pride died. Tis was the first finish to come up on Google - i couldn't decide on one.
M-1:
Famous for being free virually everywhere, yet never really looking like it was going anywhere. Also famous for robbing us of Fedor in the UFC.
Vale Tudo Championships:
Famous for being absolutely brutal - "No Holds Barred" fighting when it was borderline illegal, groin shots were standard, and everyone that came through it at the top was a monster. Chuck, Wand, Pele, Goodridge - this was their world. Shit was brutal. People got hurt.
EliteXC:
Famous for being shady as fuck, yet still fun - never afriad to put on a freakshow or give aged fighters a payday. Nobody ever knew what was going on with them. Good providoer of new talent.
OneFC:
Fanous for being The Chinese alternative - different rules, almist Pride in a cage, except in a shady Chinese was with complicated rules. Could go anyway but has some great fights and some good fighters murdering bums. Also for this kick:
WSOF:
Famous for being a dependable source of new talent, solid, but not so easily watchable for overseas viewers. Underrated, yet forgettable.
Rizin:
Famous for being the new kid in town. Could it be the next PrideFC, or will it be another Bodog? Famous right now for flirting with Floyd, and its potential. And for Krazy Horse.
Let me know if I forgot any good ones.