Good nutrition is better than any supplement. After that just drinking a post workout shake with protein and dextrose/maltodextrin will get you a long ways. If you are willing to spend a little more money then creatine and BCAAs are helpful.
If you go to the journal section of this site and click on the Complete Dieting Programs link the 13 Weeks to Hardcore Fat Burning article does a good job of covering nutrition and supplements in general. (I would link it but I don't know how to).