Other than a multivitamin and protein powder I'd say save your cash.
Ephedra is wonderful for cutting, and dirt cheap!
In the past few year i've taken:
Swole (v2)
Nitroxyn2 (PVL)
N Fusion (Neo Genixx)
Garg (PVL)
Redline (VPX) - Overpriced shit, ephedra is so superior.
Trib Fusion (Neo Genixx)
Endorush (BSN)
And a few others. Nothing has really done much. Best thing for a natural is good quality foods, lots of water, sleep and to hit the gym. I've come to the conclusion the only real 'supplement' that helps comes in a vial, and the vast majority of 'sport supplements' are snake oil.
In conclusion, save your money and buy an extra steak or two a week.