Most effective workout?

[ShowingBones.]

Hey. Well I've just been wondering what is your most effective workout you do?
Your favorite workout? One workout that REALLY shows results? :)

[Kazeriu]

My favourite workout is running or some aerobics in my room. I can stick on a movie or some music and time passes really quickly for me so I last for longer. I also quite like having a go on the rowing machine b/c it uses arms and legs which makes me happier after 20 or 30 minutes on it as I know I've done a good workout.