You can find short reviews of the original Star Wars trilogy movies here.
In 2010 the original Star Wars movie became 33 years old and in order to honor this anniversary we are listing 33 reasons why the trilogy is what it is. All of the points below refer only the original Star Wars trilogy or a particular movie from it. The prequel movies could be a matter of a separate (not so positive) list eventually.
Here goes the list, not ordered by importance or in any other particular order:
1. The original Star Wars trilogy was pretty simple to understand (unlike the prequels).
2. The trilogy had an actual story. It was not a chaotic mess of events.
3. The original 3 Star Wars movies were very realistic (for a sci-fi movies at least, and again unlike the prequels).
4. The visual effects were really great (even compared to many of today's movies).
5. The sound effects were great.
6. The music was a perfect match to the narrative.
7. The music was outstanding on its own and easily recognizable and memorable.
8. The costumes were really cool, some of them becoming a definitive part of their corresponding characters.
9. The innovative textual opening of each movie contributed to the unique appeal of the series.
10. The trilogy had Han Solo. This should be self-explanatory. :)
11. The trilogy had Darth Vader. It's another self-explanatory point.
12. Yoda was there - the mystical character on Dagobah, not the flying ridicule from the prequel trilogy.
13. Ewoks were there contributing to the overall fun of the series and bringing something new in the somehow repetitive Episode 6.
14. There were not personal computers in every home yet - people still went to see a good movie multiple times.
15. Instead of playing electronic games many people were trying to play Star Wars roles live.
16. The 3 Star Wars movies were thought of as a whole and coherent story at one point (although not at the very beginning) and the 2 sequels were not made just because of the unprecedented box-office success of the first movie.
17. The initial sequel (The Empire Strikes Back) was of no lesser quality than the first Star Wars movie, if not even superior to it.
18. The trilogy was easily franchisable.
19. The backing Star Wars universe was in times bigger than the part of it shown in the movies and all of it was very well exploited commercially.
20. There were no high expectations if any for the first movie so it took the movie world by surprise multiplying the overall effect of its success.
21. It was a story created without pressure from a film studio, written by the author the way he wanted to be.
22. The original Star Wars trilogy was based on a simple "good vs. evil" plot with universal appeal. The movies were even shown in the socialist countries behind the "iron curtain".
23. The unique universe created by the original trilogy had not been reached even close by any other movie/series until then.
24. The trilogy builds up on classic archetypes - an evil Emperor magician, his "right hand", a princess in trouble, knights with swords and so on.
25. There was a love subplot presented not in a boring but in a rather funny and entertaining way.
26. The movies were populated by lots of interesting non-human characters never seen in a movie before.
27. The trilogy had one of the greatest twists in movie history - the good and naive Luke Skywalker found that the evil lord Darth Vader is his father.
28. The humor in the original trilogy worked very well - everything intended to be funny (like Han Solo, C-3PO, Yoda, etc.) was funny.
29. The movies were pretty optimistic, even the otherwise darker "The Empire Strikes Back" had optimistic touch.
30. The original Star Wars trilogy did not look like a Star Wars rip-off (as many other sci-fi movies including the Star Wars prequel trilogy did).
31. It was the right time. Obviously.
32. The force was with the Star Wars movies (but not ALWAYS, only for the original trilogy).
33. This is the spot where you are welcome to put your own reason why Star Wars is so special (if you think it is)...