I think the top three would be the PS2, PS3, and PS4.
PS2 for having generation defining titles like God of War, Ico, Shadow of the Colossus, and the Jak, Ratchet and Sly trilogies, Gran Turismo 3 and 4. It took the blueprints of the PlayStation style the PS1 established and further developed upon them. Honestly, the PS2 era really was when the "PlayStation" aesthetic really came into its own. People forget how foundational this system was for the brand.
PS3 started off a bit weak. But once Sony ramped things up, then arguably became the greatest first party lineup that generation. Big titles like the Uncharted and Resistance trilogies, The Last of Us, the Infamous and Killzone games. Platformers like LBP, Ratchet, & Puppeteer. And truely unique and unusual games like Folklore, Heavy Rain, Journey, Everyday Shooter, Eye of Judgement. Huge amount of variety, and most of it very high quality.
PS4 also doesn't get enough credit sometimes. It may not have as many AAA releases as 2 & 3, But the games it does have really delivered. Horizon, God of War, Marvel's Spider-Man, Bloodborne, Ghost of Tsushima, Dreams. And you still had a wide variety of other stuff like Knack, Astro Bot's Rescue Mission, Gravity Rush 2, The PlayLink games, Entwined, etc.
If I had to pick one though... It's the PlayStation 3.







