The burpee is the most versatile and complete exercise that I know of. It can be done anywhere where there is at least one meter wide and one's height+1/2meter long of floor space for the body to accommodate.
It can be done in Spartacus mode(1 minute of workout followed by 15 minutes of rest, for 3 rounds), or in maximum-repetitions mode, in which one exerts the maximum number of repetitions for a given exercise, varying from one type to the other, with or without small pauses in between, as many rounds possible.
What's nice about burpees is that no equipment is necessary(although adding kettle/bar/dumb bell weights causes more challenge), the space required is minimum, the amount of time is also reduced(if only 1 round is exerted, it will last only 12 minutes), the type of exercise is versatile, ranging from cardiovascular exertion, to endurance to weight lifting(if weights are added to the formula).
It really is the most versatile exercise I know of. There is a caveat though. It is gruesome. It really is going to activate one's heart rate rise, the majority of muscles will feel sore after a while, and a sweat pool at the spot is almost assured. That's why it is worth it. Because it is worth it. It will build muscle, will power and burn a lot of fat. It is one of those exercise sessions that not only sculpts the body but also cleanses thy soul. It makes one a better person.