Circuit training
One of the best and probably most under rated ways of getting fit is circuit training no real equipment is needed and you can use your own body weight, check out the physiques on gymnasts and they do very few weights if any.
Take a look at this easy to no equipment circuit, 6 exercises, 30 seconds on 30 seconds off, will take less than 20 minutes, perfect for training at home.
Circuit 1
Press Ups, Squats Sit Ups
Circuit 2
Dips, Lunges, Sit Ups