This movie was total fun. I can't believe it didn't get more attention when it was in theaters. Wait, actually I can. Because it is SO not a normal movie. Harry (Robert Downey, Jr.) narrates the story directly to the audience to great effect. He and Val Kilmer are absolutely fantastic together. I can't really begin to explain what the story is without needing to essentially give you the entire plot (murder mystery; Harry is an "actor" and Kilmer's Perry is a gay detective), but just rent it and enjoy.
A couple of my favorite lines from the movie:
Perry: Did your dad love you?
Harry: Only when I dressed up like a beer bottle, how about you?
Perry: Well, he used to beat me in morse code, so it's possible, but he never said the words.
Perry: Look up idiot in the dictionary. You know what you'll find?
Harry: A picture of me?
Perry: No! The definition of idiot. Which you f**king are!
Perry: [to the audience] Thanks for coming, please stay for the end credits, if you're wondering who the best boy is, it's somebody's nephew, um, don't forget to validate your parking, and to all you good people in the Midwest, sorry we said f*ck so much.