Better than the sequels
I think the reason this movie is so much better than the sequels, isn't because it's more fun and thrilling, but more importantly it was conceived as an actual standalone movie... it has a conclusion, a climax, unlike the sequels, it's not just an episode in a series buying time until the next installment...
I think this is reflected in a lot of movies these days that feel like nothing but set up and payoffs without any meaning, because there is always another episode, another chance to change things and take our attention away... End of credit scenes are a symptom of this as well, even before we leave the theatre, we're already taken out from the movie experience by seeing what is, effectively, an ad for the next one...