Just been browsing this forum and it seems everyone wants to both 'bulk-up' and 'cut-up' at the same time. Well, from experience, here's something that works, if you have the time and the b*lls:
Find a 100 metre track/field, preferably with a nice big hill.
Sprint (and I mean sprint not run fast) 100 metres.
Jog 200 metres.
Repeat 5 times.
Walk slowly back to start again.
Sprint (and I mean sprint not run fast) 100 metres.
Jog 50 metres.
Walk 50 metres
Repeat 4 times.
Walk slowly back to start again.
Sprint (and I mean sprint not run fast) 100 metres.
Walk 100 metres.
Repeat 3 times.
You'll probably be close to throwing up at this stage. Take a 5 minute break. Find the nice hill. Sprint to the top, jog back down. Repeat 3 times. Take a 200 metre jog. Repeat the hill sprints.
Take a 5 minute break. Then finish off with some nice hard 50 metre sprints, maybe 3 just to really get the juice flowing. You'll find that this is almost easy.
Now this is NOT for beginners. You have to be in ok shape already or you will likely kill yourself. You need to have a base of sorts to work from. If you think you're hard do 5 sets for everything, that's the eventual goal. If you warm up first with a few sprint drills (search the web) every time you'll get faster and the drills will seem a bit easier.
The benefits:
Extreme cardio-vascular stress means you get fitter.
Putting the muscles under maximum exertion (ie sprinting) boosts testosterone levels - we should all know the benefits of this.
Adding a weight training regime as well means the muscles fully utilise the body's increased testosterone production. You will get stronger.
Putting the body under such stress will mean you will be burning calories for hours afterwards.
My tip, don't be so concerned about the look. If you're getting fitter, faster and stronger and your diet is good - the results will take care of themselves.