You guys are weird. Is this the Top 10 MMA Fighters or Your Favourite 10 MMA Fighters?
This is the top in each weight class.
Heavyweight 205 +: Emalianenko Fedor, Rodrigo Nogueira, Frank Mir
Light Heavyweight 185 - 205: Wanderlei Siva, Vitor Belfort, Randy Couture
Middleweight 170 - 185: Matt Lindland, Murilo Bustamante, Dan Henderson (Murilo and Dan could be debatable because their rpime fighting weight is 185 but in Pride they fight at a higher weight, closer to 205)
Welterweight 155 - 170: BJ Penn, Matt Hughes, Sean Sherk
Lightweight 145 - 155: Shaolin Ribeiro, Takaori Gomi, Hansen
Featherweight - 145: Pequeno, Kid Yamamoto
Pound for Pound best fighter in the world for free format / limited rules combat sport: BJ Penn (in his last three matches has defeated former Shooto lightweight world champion Takanori Gomi, went up one weight division and finished UFC Welterweight champion of the world Matt Hughes and went to K1 Romanex and schooled linear UFC belt lightweight champion Duane Ludwig [who KO'd Jens Pulver]. In short BJ Penn has unofficially unified both Shooto and UFC lightweight belts and won the UFC Welterweight belt, before being kicked off the UFC.