One of the Best Exercises...

It's hard to beat the burpee in its overall bang for the buck. Besides the squat and push-up, this one is one of the most awesome equipment-free exercises to do. Just don't do it on a full stomach. I really love burpees!

Coming to think of it, my top five favorite exercises are as follows:
#1 -- Squat
#2 -- Burpee
#3 -- Push-up
#4 -- Dead-lift
#5 -- Kettle-bell overhead swing

Honorable mentions in no particular order: clean and jerk, snatch, bench press (incline, decline, flat), Arnold press, bicep curl, flys, salamander (aka seal crawl), push-press.