Weed - young age introduced me to the idea that not everything you were told was true and that things really were hidden from you, alongside that the world of drugs although I'd drank lots before I just loved weed, it's my drug.
Opiates Oxycontin/Fentanyl - pretty sure as a result of using these from the ages of 14-16 that I was left with anxiety and some form of depression, those were important ages to get out and learn about things, rather than sitting with a nod on for weekends on end, although I'm not sure if it was there before.
LSD - I truly believe acid made me a better person, more open minded and less quick to criticize or be rude to others. I felt a lot more conscious of my actions afterwards and strive a lot more to please others, although I've always been a loyal person I'd say my early teenage years (tried acid at 15 I think) before that I was a bit of a dick to some people, acid and weed really calmed me down a lot but now I've terrible anxiety etc. It was my first psychedelic (although had tried weed/salvia before don't consider it the same). Salvia just showed me how powerful drugs could really be, it scared me in a way.
Alcohol - Without this stuff, I'd never have had my first kiss, lost my virginity in such a ridiculous way or gained the confidence to get out there and make some friends.
MDMA - reinforced in me my love of music, I've no interest in television and movies, music is were it's at for me. Taught me how to dance without caring and that first time at a rave on MDMA seeing so many different types of people come together in one place, for one thing, music, really changed my life. It's a pity I don't see raves as the same way now anymore, but still enjoy them.
Probably the main ones for me. Drugs have had a massive influence on my life.