I've been on all of them. I found dexedrine to work the best but would end up with headaches from clenching my jaw all the time. lol. Adderall is pretty decent at high doses. I'm on provigil now. I eat them like candy though. I did order this stuff called smart coffee though that worked better than all the stimulants I've been on, so will let you know how that goes. The sample I had went well.