My favorite to do myself would have to be IV hydromorphone. When I'm on stimulants or Lyrica I want to get out, do something, talk to people, etc.
Quit getting drunk, haven't in about two and a half months, and I am very happy to be able to say that.
Don't like pot, makes me paranoid and can't think, can't sleep, can't eat, so it really has no therapeutic value for me right now. If I developed arthritis or something I probably would.
Benzodiazepines are nice, but only when mixing with another drug. Never done a barbituate to my knowledge.
My eyes play so many tricks on me being legally blind for lack of pigment that my eyes have so I don't think I would enjoy a hallucinogen, though I have never tried one.
Never really had the opportunity to try research chemicals, unless you count JWH analogues, which I did not like one bit.
Dissociatives are very nice to do by yourself, second for me only to opiates, and dextromethorphan is great for opiate withdrawals.
Conclusion: Opiates/Opioids, in the case of Dilaudid, IV.