Dramamine.
What it did to me and my friend ...
That trip made me bug the fuck out, I was talking to people that weren't there, woke my parents up at 3 in the morning because I thought my mom's friend was at the door (I answered the door bell and saw her), my friend DROVE HOME and almost got arrested (I thought he was still at my house because I was still having conversations with him all night), god knows how he got off of that ... imaginary cigarettes, your wallet that vanishes every time you try to pick it up ... then throw in flash backs weeks after, and the unknown damage it did to my brain, I fuckin hate the drug.
But I guess the drug that I should hate the most, or the drug class, is Opiates ... they have ruined so many of my friends and it is so god damn depressing. My (former) long-time best friend recently got arrested for possession of 10 grams of H and going on a shopping spree with his grandmother's stolen CC, not to mention a possibility that he stole $1300 from me (not something I can prove). But, since I still use occasionally, I can't say I hate it the most.