Johnny Depp as Hunter S. Thompson in Fear and Loathing in Las Vegas
In a way, this doesn’t technically count, as Depp’s character in the adaptation is Raoul Duke. That’s Thompson’s literary alter ego, sure, but it’s also a fictionalization. Nevertheless, Depp did live with and study the real Thompson for months, so for that reason it does definitely count. Then again, there is some exaggeration in the writer’s persona and Depp’s portrayal. Then again, you could go mad thinking about it.