I'm a bit of a casual, but here it goes...
1. Alcohol (it's the most social among my friends)
2. Modafinil (it helps me get through a slow day at work and works much better for me than Adderall for focus)
3. Cocaine (It makes me feel on top of the world and would be #1 if I hadn't promised my girlfriend not to use it anymore and kept that promise)
4. Clonazepam (works nice as an anticonvulsant, anxiolytic and sleep aid)
5. Hydromorphone (despite limited experience, it did help eliminate post-surgical pain and felt sedating/euphoric)