I'm going to have an unpopular opinion.
Phantom Menace was probably my favorite. They spent way too long on Tatooine, but I still liked the way the movie flowed. I didn't dislike Jar Jar. I'm probably a bit biased, because my father got me into Star Wars at a very young age where I was too young to really appreciate it. I re-watched 4,5, and 6 all right before Phantom Menace came out and absolutely loved the series. Going from 1970s CGI to 1999 CGI mere days after really seeing the series for the first time was absolutely amazing. Seeing Jedi's at their peak form right at the start was amazing to me, as they never really fight like that in 4,5, and 6. The best duel in the series is probably Obi Wan and Qui Gon vs Darth Maul, too. It was this movie that really set up me getting into the Star Wars universe the most. This is obviously a very objective opinion based on circumstances, I was 11 years old when I watched the Phantom Menace.
The "best" Star Wars from my critic point of view was probably episode 6, Return of the Jedi. It merged fantasy and sci fi together perfectly. The light saber action was great. Luke started slipping into madness a bit, and was only able to defeat the emperor thanks to the help of his father going soft after being defeated. It was not cliche at all and I loved how gray they made it. It had a happy ending, there was some romance finally, and Luke got to see his father as a force ghost. It was all very touching.
The most iconic scene in star wars is probably the Death Star being blown up in episode 4, though. Even the power puff girls ripped it off.