Bug-free isn't a fair expectation. But whatever happened to QA testing ensuring no killer bugs? How can games get released where the basic netcode doesn't work, or the voice chat craps out? Once upon a time a console company wouldn't allow such buggy games. They'd reject the game and tell the devs to go fix these bugs because they weren't providing a good enough experience for their platform. We still have that in theory as evidenced by Under Siege's long-overdue patch, so how come it's not in force universally and ensuring 1) games mostly work and 2) where there is a game-stopping bug, devs are held to account and made to get a fix out in short time? If you bought a LEGO game on PS2, it worked flawlessly at 60fps. Buy a LEGO game this gen and you get tearing or framestutters and bugs that trap you and prevent progression and you just wait and wait until maybe a patch is release. Does that not strike you as a demise?
Maybe it's the games I buy, but I've never had any problems like that. The only problems I've experienced are server issues on the back-end for EA titles, including the Battlefield games. I think NHL 09 may have had a voice chat problem, where not everyone would be able to hear one another in the game. So far I have not purchased a game, retail or download, that had any showstopper bugs. Lucky I guess?