In order (IMO)
1- ACB: great cards this year, looking forward to a wonderful 2017 for them and IMO already bigger tham M-1
2- KSW: They've some really known names and they put on great shows, something that i really like of them is that you always know when they have a card...
3- TitanFC: Tons of good names and really entertaining fighters, even more watchable after the move to FP
4- LFC and RFA (now LFA): The best way to make into the UFC is to fight here, they have a tons of event and really good matchmaking...
5- Cage Warriors: Biggest one of the UK, a lot of stars came of here, theyve got some really good prospects
6- BAMMA: Closest competition to CW, they are the second biggest one in the UK
Then we have promotions like DEEP, Shooto Br and Jp, Pancrase that make cards ussualy but don't generate a lot of hype...
And then there are new ones like EuroFC....