Keith Richards has always been quite far up on my 'uber cool' list. He always seems so chirpy and happy too with his lifestyle, not a drug casualty celebrity looking for sympathy in rehab. (Same goes for a few others musicians like Jimmi Hendrix, Jim Morrison, Bob Dylan, George Harrison, Lou Reed, folk that hung around Andy Warhol's Factory).
Also, Steve Jobs saying that taking LSD was one of the best and most important things he has ever done.
Terrence McKenna and all his whacky talk about 'machine elves' etc.
Prof. John Lilly and his dolphin communication studies and use of ketamine and LSD while in a sensory deprivation chamber that he invented!
Timothy Leary and his 'turn on, tune in, drop out' phrase and he is a bit of a legend within 60s drug culture.
Irvine Welsh novels that contain numerous stories revolving around drug use (plenty of other authors too, but Welsh's material is hysterical).
Bill Hicks and his stand up routines involving accounts of his drug use.
I find most of the people above fascinating in someway, they might not have influenced my own drug use, but I definitely like hearing or reading about theirs. There are plenty of other famous people who are more at the 'casualty' end of the spectrum, whose stories are more amusing, or even tragic, than fascinating to me.