That is a clip from a WCL fight, which is American kickboxing, not MMA.
The most famous example everyone likes to use is "The Crow" landing the spinning back kick on Charles McCarthy, but as another sherdogger in this thread already pointed out, he hasn't landed that kick too many other times.
Spinning back kicks are great when they land, and make for sweet HL reels, but they are a low percentage move in MMA.
Axe kicks were also mentioned...the best use I have seen of axe kicks in recent memory is GSP using them to the body of Mayem when he was on his back.
