By now, you've probably heard about the Mayweather vs. Ortiz fight that happened over the weekend. Some of you might have caught the roast of Charlie Sheen last night where Mike Tyson railed on the Charlie (not 'railed charlie', that's another story). Some of his jokes hit hard, but certainly weren't as jarring as, say, his knockout punch against Frank Bruno. Since today (September 20th) is National Punch Day, we thought we'd show you some of the most devastating punches ever caught on camera. Check out the gallery and videos after the jump.