I liked the whole series. I found the newer 3 slow at times but on the whole a fantastic series. I can't wait for number 7
I'm partial to the first three (episodes 4,5,6). Episodes 1,2,3 were OK and seemed genuine to the original but they were VERY boring at times, within the movie.
I enjoyed all of them! I liked the older ones (and still do) and have fond memories of watching them...I like the newer ones that explain so much more!
I liked them all the same but I liked 'Return of the Jedi' the best.
They are simply not as impressive as the first ones, because now the cinema is constantly spewing sci-fi computer animation rich sequences. This is pretty much it.
I enjoyed IV, V, and VI and was looking forward to the prequels when they were announced. Off I went to see the first of them and was disappointed to find it to be all action and special effects with little storyline. I didn't bother watching II and IIl.
Personally, I always thought the story line seemed to be a distant second to trying to show off the technical side (CGI, etc) and selling merchandise.