I consider myself to be a fan of Terry Gilliam's movies but I'd never seen this one due to lack of interest in the subject matter, I finally watched it and I was entertained for about an hour, it's a shame the movie runs for nearly twice that.
Johnny Depp and Benicio Del Toro both deliver excellent performances but given the fact that basically nothing happens for most of the movie other than the main characters going on a drug fuelled bender for the entire film I found myself getting bored even with Gilliam's unique visual style.