I find with Mass Effect 2, if I try and load the game without being connected to XBL, my DLC will become corrupted, and I can't load my game because of the corrupted DLC, which I have to sign back into XBL, redownload the DLC, and then load my game in order to play.
in the news thread about Ubisoft's DRMI suggested a way that scans our rectums to ensure only the registered rectum plays the game.. It's about the only place DRM could go from here.
A long while back I made an april fools post about a DRM that required you to keep constant pressure on a biometric fingerprint scanner to play the game. Doesn't seem like such a joke now.
My main issue with steam is that sometimes it will just say 'That game is currently unavailable" even if it's a single player game. Want to play Portal? Steam won't let you? screw you, that's what you get.
But all in all, I love Steam as a concept, I just wish it was a littler friendlier with the online activation.