Whats the quickest way to gain muscle weight?!

Whats the quickest way to gain muscle weight?

I'm working out at least 3 days a week (2hr workouts) right now, doing all the protein shake stuff, eating well but can I do more? What kind of diet, how many days a week at the gym, etc.

First of all, a 2 hr workout is too long. After about an hour your body becomes catabolic and starts to break down muscle. You should work out about four times a week with about hour long workouts. Try to incorporate alot of compound exercises into the workouts such as squats, bench, deadlifts, cleans, etc. As far as diet goes consume about six small meals a day with 1 to 1.5 grams of protein per pound of bodyweight. Do high intensity cardio twice a week. Also if you want you can try creatine. Take the powdered form 30min before workouts. Hope this helps.