With Brock Lesnar's sudden retirement, the UFC was left with a void for a top PPV draw to go along with Georges St-Pierre. Besides a guaranteed high buy rate, Lesnar brought a lot of excitement and interest to whenever he was on camera.
The same could be said for the fighters that comprise this list. Some were champions and will go down as legends of the sport, while others never achieved a higher status than journeyman. Either way, it's clear these fighters will be missed for a number of reasons.
MMA is a sport that calls it's competitors back, and walking away isn't so easy. If these fighters are truly able to step away forever, they will surely be missed.