I think there is a myriad of reasons, but let me just name two that I think are the most pertinent from today’s perspective:
When it came out, everything about it was quite fresh, the non-chronological narrative, the cool gangsters, the episodic structure, the soundtrack, the bursts of violence. In that specific mix, it was unlike anything people had witnessed before
I think it’s a “hang out” movie, the way Quentin describes these himself: as an audience, you find these characters so three-dimensional, you’d like to hang out with them, spend time with them, and you actually do. The film is quite long so by the end you’ve been through two or so days in the lives of them and oh boy what two days those have been. It’s wild, even though a lot of what actually happened (e.g. the boxing match) you never get to actually see…
My take is long: 3 separate yet equal films of the master, excellent acting by ALL of them, fantastic and QT’s wild and intelligent imagination that is only from his mind. It is a monumental classic!!
Mike D.
The storytelling is unique (non-chronological)
There are lots of theories to be had about the story (briefcase, Wallace’s neck wound, divine intervention)
The dialogue is brilliant (foot massages are something special)
The music choice really contributes to the atmosphere (all these old 60/70s songs)
And the characters themselves are something special: you don’t know them, yet you care about them.
And those are some major points why I think Pulp Fiction is brilliant,