Might be worth having a read of the side effects if you do plan on using Dianabol: http://ic.steadyhealth.com/side_effects_of_dianabol.html
IMO, you can't beat a good healthy diet. A lot of these modern day expensive powders, are packed full of chemicals and E' numbers which can't be doing you any good.
It's also important to remember the triangle balance of diet, sleep & workout. You need all three to achieve maximum muscle growth.
Sleep is the big one that a lot of people neglect. Work-out hard, sleep minimum 8 hours a night, lots of strong proteins (fish, chicken , eggs) in your diet and you won't be far off.