That Eph/Caffeine/Aspirin stack mentioned above is a tried and tested favourite. A lot of bodybuilders are going crazy over Melting Point at the moment....

http://www.discountanabolics.com/p/DS05

It's a modified fatty acid rather than a traditional thermogenic. Safety, etc I'm not sure about - all this shit has risks attached.

Was tempted to use some myself, but not gonna go down the untested chemicals route until I finish the get off your ass and do more cardio, stop drinking beer every night and eat properly approach first.