I have not played D3 and probably won’t, just because I don’t like the forced-online aspect. Just to show you how far behind the curve I am, the next games on my list are Portal 1 and Planescape: Torment.
Don’t feel bad about the. The oldies are the best! I’m an avid Sim City 4 player, and I have numerous large cityscapes I visit often. I refuse to get Sim City 5 for the same reason you won’t get D3: always online required. No thanks, EA!
I love Steam for the older games and the fact that I can play anything I want when I want to play it without having to dig a CD/DVD/BRD out of a cabinet or ISO over my NAS.