At the moment i'm playing Black Flag on PC and GTA V on PS3, it's quite a contrast going from totally maxed out 1440p at solid 60fps to the 720p barely any AA 30fps of the PS3 but I would call it unplayable. I love GTA Online its great and I will always stand by it on any platform.
Like yourself sometimes I go off gaming and get more involved with playing with hardware but I think that might have something to do with the fact i'm just not that great at gaming. If I play online on PC with mouse and keyboard I get owned and feel pretty noobish but on PS3 I feel at least my combat skills (GTA) are on par with anyone and I can enjoy playing a more tactical higher level of game. Having played Assassins creed so far without my pad I think i'm improving a bit but I still think that's probably why I don't seriously game on PC, I do like looking at the pretty pictures in single player though lol. I would hate to be a total PC elitist, I enjoy playing on my PS3 and with my friends on their xbox's casually.
Just a suggestion from me maybe give Mafia II a shot? It doesn't look too dated and it's a really enjoyable story IMO and there's lots of DLC if you do find yourself getting caught up in the nostalgia.
JR