OP clearly never played games in the DOS/Win95 days.
I wasn't really considering older games when thinking about the worst games I've played. Back then I didn't have as good of a grasp on what was good and what was bad. I really only played doom, wolfenstein, and descent back then. Loved all those games to death.
Back then the line between good and bad wasn't as pronounced as it is these days.
Many modern releases are unforgivably bad these days in game development. It's pretty sad when a few modders are releasing better content than huge development teams with a lot of monetary backing. Quality in the gaming industry just seems to have taken a nose dive in favor off quick profits of the less discerning console masses.
I feel that more and more PC gamers (heck consolers too) are getting extremely fed up with the hype surrounding sub par releases, and game sales will soon start reflecting consumer's attitudes.