Metro 2033. Serious answer, PS4 and XB1 are getting redux editions to match it. You could say that from that point on all PC ports could be considered next gen in comparison to the ps360 editions, that isn't to say there is a huge difference between PSbox41 PC and 360 games at all.
It has become a very gradual increase between the 2 gens, it feels more like an expansion pack semi-generation than a full upgrade, it definitely does for most PC gamers who have 1-3 year old systems and haven't been pushed to upgrade.
"You know what's most annoying about hearing neighbors having sex?, When it's too quiet*" - Umbongo