Reloaded and Revolutions are pretty convoluted. They make sense if either A) you pay eye-drying attention or B) you read analyses online afterwards.
The first Matrix - i.e. the good Matrix - isn't convoluted. It's not really even complicated. The exposition is very straightforward and even pretty interesting; it's conducted through kung fu fights, leaping over buildings and badass monologues in "the desert of the real." The whole point of a high-concept movie is that its premise can be easily summarised, as it is with The Matrix - humanity is trapped in a computer program, batteries for the machines, and only The One (Keanu Reeves) can break the rules and set us free. Boom. Sold.
The Matrix, for me, is probably the greatest action movie all-time. I love Paul Vorhoeven - Robocop, Starship Troopers, Total Recall - and John McTiernan - Predator, Die Hard - or even James Cameron - as if you need reminding what he's done. But The Matrix! Oh-ho, The Matrix! It's so well choreographed, so well written; even the soundtrack is incredible. It treads the line between badass and cheesy on so many occasions, but always ends up on the right side. It's smart and funny and exhilarating. It's a blend of kung fu cinema and Hollywood science fiction. It's basically everything I want from a movie. The Wachowskis know what they're fucking doing.
Pulp Fiction, on the other hand, is also fucking awesome. Yeah, I was hoping this was going to be an easy decision too. C'est la vie. Obviously, there's the dialogue, the narrative structure and, well, that's basically Pulp Fiction boiled down to its basest parts. People think Quentin Tarantino's films are about pulpy action for some reason. Other than perhaps Kill Bill Vol. 1, they're not - they're about characters talking to each other. Tarantino's movies are about being hysterically funny or effortlessly cool or unbelievably tense - and all just through conversations. Don't get me wrong, real people don't talk like Tarantino characters do, but it's effective, so who cares? Pulp Fiction is the example of that.
Pick either. Flip a coin. Red pill, blue pill.