There's at least a gazillion reasons that Pulp Fiction is the coolest movie ever made. I am not stating that it's the best, but after fifteen years of testing, the coolest.
Before I simply list a few, I thought I'd start out by saying that a "conspiracy" email went viral detailing all the mysterious little things in the film that go unexplained... this email nicely wrapped up all the issues with credited analysis and put a bow on everything including the Ving Rhames back-of-the-neck Band-Aid, the glowing briefcase, the biblical quotes and the shots at point blank that, er, miss. Here's a hint of these related theories. I'm sure if you Wikipedia or Google this stuff you'd find much more. Wish I could find that old email for you. It was from '95 or something. The movie spawned my first viral email. Cool.
As always for famed director Quentin Tarrantino, he picks an original and punchy soundtrack of eclectics and stuffs the cast with unique actors portraying distinctive roles. Harvey Keitel, Rosanna Arquette, Samuel L. Jackson, Uma Thurman, Bruce Willis, Eric Stoltz, Rosanna Arquette, Tim Roth, Ving Rhames, Christopher Walken, Steve Buscemi, and ultimately, John Travolta -- introducing, redefining, solidifying and resurrecting. Totally cool.