It's simple. Figure out your SO's interests and don't just assume she/he/they can only play "easy" games. If your SO loves watching fantasy movies, find a fantasy video game.
The rise of sim-style shooters has destroyed the series. Call of Duty isn't wacky enough to be an arcade shooter and it's not realistic enough to compete with Arma or Battlefield. They need to pick a lane and stick to it.
The Vita is a wonderful piece of hardware, but it didn't do too well, so don't expect much further support from Sony. In any case, if you find a good deal it's definitely worth it.
If you don't care about collecting and just want to play some games, I would sell it and set up a Raspberry Pi emulator. There is something special about playing the actual console on an old TV, so give it at least one play!
If it's normal to find the console at a thrift store it's probably retro. In any case, I think PS2 will be considered retro in a couple of years. I wonder how those games will stand the test of time, since 8/16-bit always looks good but that's not the case with 3-D.