Vampire Bloodlines, Rome: Total War, Half life 2, Far Cry, WoW. It also had massive disappointments in KOTOR2, Doom 3, Thief: Deadly Shadows and Fable. Bloodlines is arguably a disappointment, but being so original it's immune from that criticism, imo.
Eighties until about 2000. After that PC gaming was pretty much dead for a decade save for stuff like WoW, until around 2010 the rise of MOBA's, Steam and browser games revived the platform. Unfortunately we won't see stuff like Unreal Tournament, the first Starcraft and Quake on PC's anymore though :(
There were a lot of good games in the past -- I remember the late 90s and early 2000s having some good ones I played while I was in college -- but as far as "golden ages" go, as much as the whole concept of the "golden age" is rooted in baseless nostalgia, this is a pretty damn good age for PC gaming. For all gaming, really, console and PC alike. With the sheer variety of what's been made available on Steam, the cost being lower than it's ever been, and the availability of many of those older games that have been otherwise impossible to find for years, it'd be hard to argue that we're in some kind of dark age.
You might very well think that. I couldn't possibly comment.