To my youngest son (born in 1994), The Phantom Menace was his favorite Star Wars movie for years. Many of our feelings about "the best" of something depends on how it coincides with our formative years. For me the original Star Wars was highly influential(I saw it on its first run, between junior and senior year in college), but the most formative science fiction movie for me was 2001: A Space Odyssey (seen on first run in a Cinerama theater).

(My son has evolved somewhat in his view of Star Wars films. I'm just glad his older brother didn't regard The Barney Movie t00 highly.)