Let’s say the PC doesn’t count and you aren’t taking into account backwards compatibility, emulation, online play, homebrew games, and the cost/availability of games.
I feel like I’d want to choose the PS3. Like the Xbox 360 it had a decent lifespan and a lot of games were produced for it. A lot of which are already some of my favorites.
The only things that would make hesitant are I feel like a lot of modern games are larger and have open worlds which I feel like that could be nice in the long run and many of my favorite games for the PS3 have been re-released.
Would have to be either the switch for Mario Kart, Super Smash and Nintendo sports when family is visiting or PS3 for FIFA World Cup 2010 when the lads are visiting. I suspect the switch would age better, though 2010 World Cup is an absolute gem.
I don’t think the single player game selection matters that much as it would grow stale with time anyway.