A fantastic submission is more impressive than a great knockout.
Both have their place in the sport of MMA, and both have caused me to spill my beer, jump off my couch and scare my neighbors with barbaric screams on several occasions, but the thing that makes a perfect submission so awesome to me is its complexity.
I can go out in the street, get in a fist fight and maybe knock somebody out cold (I could also get knocked out cold, of course).
Most everybody can ball up their fist and swing it in the general direction of an assailant.
However, not everybody can wrestle an assailant to the ground, establish a dominant position and then submit him/her with a fancy submission.
This example has obvious flaws (what about a wheel kick—not everybody can do that!), but my point here is that a submission, in general, takes more skill to pull off than a knockout. You never really get "lucky" with a submission; you either know how to do it and pull it off, or you don't.
To honor this sweet science of smooth submission, I present to you the finest "Submission of the Night" performances in UFC history.
As a note, the first such award was given out at UFC Ultimate Fight Night 4 when Dan Christison caught Brad Imes with a third-round armbar. So, any submissions before this date were not considered for the list.