Keysii fighting system. (may be spelled wrong).
I just stick with good old Muay Thai.
References :

By Politicalcorrectnessisgay on Jan 21, 2009

Lots. The two you named must be local, because I haven't heard of them.

Dream (Japanese company)

Pancrase (Japanese company)

Shooto (International company but based in Japan)

Cage Rage (UK company)

World Extreme Cagefighting/WEC (comes on the VS. network in the US)

King of the Cage

Affliction

HDNet Fights

Strikeforce

Sengoku/World Victory Road (Japanese company)

TKO (Canadian company)

Spirit MC (Korean company)

M-1 (Russian-based company)

HOOKnSHOOT

Palace Fighting Championships

Ring of Fire

DEEP (Japanese company)

Gladiator Challenge

ZST (Japanese company)

Gods of War

plus countless assorted smaller promotions.

Also defunct promotions like Pride, Elite XC, International FIght Leage/IFL, and RINGS.
References :

By callsignfuzzy on Jan 21, 2009

There are loads but here are the main ones

DREAM FC (Japan)
Sengoku (Japan)
UFC (America)
Affliction (America)

These are the biggest players in the MMA world.
References :

By Nav on Jan 21, 2009

Just trying to add the ones that the above contributor left out; off the top of my head:

K-1 Heros [Tokyo, Japan]
MMA Xplosion [Las Vegas, NV]
Rumble World Entertainment/ROTR [Hilo, HI]
Smackgirl [Tokyo, Japan]
Super Impact MMA [St. George, UT]
Total Combat [San Diego, CA]
Tuff-N-Uff [Las Vegas, NV]
X-1 [Honolulu, HI]

E
References :

By DeltaSigChi4 on Jan 21, 2009