The original star wars trilogy is the best there is.
its impact on cinema aside, they are a great set of films starting with the simple story of a farmboy becoming a hero, to the brilliant empire strikes back which shows us how sequels should be made. To return of the jedi which though to most the most flawed of the trilogy, brings a satisfying conclusion. Doesn't get better than that. Just on film making standards alone, it's the best.
Why do the recent cgi fests not top it in my mind? because of the writing mainly. I can't really remember any stand out lines from lotr except "give me the precious!"
While almost every line in star wars 4-6 is memorable and perfectly acted by the cast. My favorite scene of the whole thing is the end when Vader goads his son into battle. "Ah, a sister... so you have a twin sister. Obi-wan was wise to hide her from me. Now his failure is complete. If you will not turn to the dark side, then perhaps she will..." "NEVER!"
Then woo hahhhh luke pwns him.