I picked 6, so PS2, which made me a lot more excited for a moment there than I expected it ever could. I'm pretty stoked about the idea, the PS2 was sorta the last console I was really into. After that it pretty much went from occasional use with the Wii and PS3 to me not really having played a game on a console in years.
What I would play? Literally the first thing that came to my mind when I read "PS2" was Dynasty Warriors, not even a specific one, but just the greater existence that is that franchise. Actually going back to DW2 in all its foggy glory sounds kinda neat though, that game and the sequels were pretty much an ever-present part of my gaming time with friends back then.
For a more serious gaming time though, not sure honestly. I spent a lot of time with PS2, played a ton of different games but right in this moment thinking about it I kinda struggle to think of a game that I would really be interested in going back to. Old games tend not to have that much appeal to me, unless it's Dynasty Warriors because man do I LOVE DYNASTY WARRIORS.
Anyway I'd probably play Dark.... Chronicle? I remember always wanting to play that game but never being able to find it anywhere so it remained this sort of elusive thing I never got around to.