For those who aren't aware of the history of PC gaming, the very first ever PC game (believe it or not) was in 1962, called "Spacewar!" on a PDP-1 computer, back when computers and such technologies were unheard of yet during those times and when no one owned a computer until the early 1980s.
Anyways, I have a touch pick between the 1990s and 2000s, since the 1990s gave us Doom, Diablo, Wolfenstein 3D, Fallout, Quake, System Shock, Civilization and Half-Life 1. The 2000s gave us Battlefield, Left 4 Dead, Max Payne, Deus Ex, World of Warcraft, Portal and League of Legends.
I think it was probably the 1990s going into the 2000s. Now, I don't mean that PC gaming is worse since then, but with the release of the Playstation in 1994, and the XBOX in 2001, consoles started chipping away at the dominance of PC gaming. When I was kid in the 80s and 90s, we had computer game / software stores (like Software ETC). Consoles had maybe a little corner. By the 2000s, if you walked into a Gamestop, you would find a shelf or rack for PC games. Now, with Steam and other online game platforms, it's hard to find any PC games in stores.
I've been playing pc games since personal computers first came out in the mid 70s (still have some of the computers too). I think the 90s were by far the best decade. Since 2000 it's mostly been about graphics, sound, and maybe larger game worlds. But there has been almost no improvement in the actual game play.
The most immersive games I've played were from the 90s. The kind of game where you turn out the lights, light a candle, and just lose yourself in the game world. That's not the same as being addictive. It's about being totally drawn into the game and it's environment.
I still play several games from the 90s. They are still enjoyable.
Another thing about 90s games, especially early 90s, was all the small indi "shareware" games. Some of those games were tiny companies, but had a huge impact on the game industry. Some of them developed or popularized entire genres of games.
Another thing about the early-mid 90s is that most games were still genre specific. An RPG was an RPG. A shooter was a shooter. An adventure was an adventure. Now, almost all game are hybrids. That's not necessarily bad, unless you actually like the pure genre games like I do.
90s for me. Although there were still many DOS games at the time instead of Windows games that took advantage of DirectX and other better technologies. Many games in the 90s also had their source codes released and have community and fanbases. Shit tons of free custom fan-made content from new levels, gameplay tweaks and mods, etc. that are available unlike the Modern day games where most only have DLC that you must buy and no SDKs ever released at all.
I think the best time for PC gaming is always the present. Unlike consoles, we're just constantly building a backlog of playable games (except for the few with compatibility issues). Nowadays, entry-level PC gaming is nearly as accessible as console gaming, meaning the player base is increasing. Not only that, but many games that in the past would have only launched as console exclusives are launching on the PC now.
I say the 2000s. That's when PC multiplayer gaming really started to take off, and reach a high level of in-depth play and the building of communities around the games themselves (such as World of Warcraft).
Now PC gaming is in a downturn, and piracy is a major issue.
200's all the way. there were an absolute SHITTON of MMORPG games coming out after world of warcraft came out. those you could buy on CD and those just available for download for free. that was the golden age of PC gaming.
I'm primarily a PC gamer and I do so for many reasons - not the least of which is that there are more games available for the PC and even those that are out for both PC and consoles are more flexible on the PC than otherwise.