Between achievements, steam history, and the Wii/3DS activity log, you can pretty much piece together that stuff fairly easily. iOS might pose a problem, but it's really just a matter or sorting through your purchases in the app store.
The Witcher 1 and 2 definitely have no party, which could be a problem for you, but they are easily some of the best RPGs of the last decade. Great story telling, decent amount of depth (especially in the second game), and an interesting, gritty world that should appeal to you.
Shadowrun Returns is a solid retread of the CRPGs of old. Speaking of which: Baldur's Gate 1 & 2, Planescape: Torment, and the Icewind Dale games are all bloody fantastic if you can get into them.
And you should probably go ahead and play Mass Effect.
Oh, maybe even XCOM: EU? That scratched a particular itch of mine for roleplaying, character building, and party-based combat. It's also really, really good.
I have no plans to get a PS4 any time soon or an XONE at all. I might get a VIta or a Wii U this fall (or just upgrade my 3DS to an XL), depending on if some good sales happen in the next few weeks. Next year, I'll probably be getting a new video card for my PC (I like to upgrade every other year)... so maybe a PS4 in 2015? Then again, a couple of crazy-good PS4 games could tip my hand early.
Uhhh... so I went and bought a Wii U the same night I posted this. (I finally had a look at some more footage of SM3DW)