This is my all time #1 favorite film, I love Hunter S. Thompson's writing, Terry Gilliam's films, and Johnny Depp & Benicio Del Toro are 2 of my favorite actors, but what makes this movie my favorite is the combination of these 4 peoples talents.
"Fear and Loathing in Las Vegas" for years was considered to be an unfilm-able novel, in part because it's a true story about ungodly amounts of substance abuse, but aside from that, there really isn't any kind of normal story structure to it, and for years no one could figure out a way to fit Thompson's free-form writing style into a typical, 3-act structure, movie screenplay. The brilliant thing a but Gilliam's film though, is that he doesn't even bother with a typical 3 act structure screenplay, but instead uses weird camera moves, lighting and editing to create a kind of "visual approximation" of Thompson's free wheeling, start and stop, style of story telling, and Depp and Del Toro tie the whole thing together brilliantly.
But the end result is a truly unique motion picture experience, and in that way "Fear and Loathing in Las Vegas" my #1 favorite, is like a lot like my #2 favorite "2001: A Space Odyssey" because there's only one "2001" and there's only one "Fear and Loathing", and you should really see them in a movie theater, but if you can't see 'em in the theater? the Blu-rays ain't bad either.