>>1328400301. Johnathan would just drink wine
2. Joseph doing ecstasy seems like a pretty natural concept, he has that touchy feely and happy aura. Maybe smoke pot and be some annoying floater.
3. Jotaro just cigarettes and Martinis or Whiskey to seem cool, never drunk and nothing that would mess with his level head.
4. Jousuke is a good boy, he wouldn't do drugs. He has that type of well thought out attitude I feel like he'd wait till he's of age to drink and wouldn't smoke.
5. Giorno wouldn't do drugs after seeing their effects first hand, but being Italian by culture he'd drink a glass of wine with dinner often.
6. Jolyne would get pressured into doing drugs, but if for example they're doing LSD she'd pull all the bad trippers through. She probably over drinks regularly if anything.
7. Johnny i just picture doing cocaine since he was young irresponsible and rich asshole. Probably drinks a lot too, but he's still somewhat aware enough to keep it under control.
8. Jousuke wouldn't do drugs of his own accord, but would probably have the funniest reactions to them out of any jojo.
All the villains would probably only drink occasionally or with meals, aside from Pucci who's fully sober.
Joubin (assuming he's part 8's villain) is a Buddhist or at least has those tendencies so he probably smokes pot rather than drinking alcohol, and has probably experimented with stuff like peyote and mushrooms.