I've only owned in my lifetime: GameBoy Color, SEGA Genesis, N64, PS1, GameCube, PS2, PS3, X360 (for a month before it broke), PS4, PS Vita, Switch.
Hard to pick your favourite. The Ninteno 64 has all the childhood memories, the PS2 has those sweet sweet middle school memories, and PS3 was my peak video game playing years.
I have to go with PS3. There were tons of amazing games, the graphics blew me away, the media features made it more useful than my laptop at the time. It was a full package system that released right when I had the most time in the world to play games.
Runner ups would be PS2 or GameCube.