For me, its the PS2, some of my favorite Sony IPs came from there. Grew up playing Ratchet, Sly and Jak, loved Dark Cloud and Rogue Galaxy. God of War is my favorite Hack and Slash series and one of my favorite series in general as well. I only played Ico and SoTC on the HD collection for PS3, but those two games were also amazing.
That being said, with PS3 it does feel like they really went all out with making new IPs and overall I feel like they did a much better job at it and marketing most of them.