Oh how quaint, someone has discovered that Wikipedia can be vandalised. I'll have to have you know that that came to us a a real surprise in 2001. Things are more manageable these days. People usually notice these things.
Not the first time this sort of stuff has happened, nor it will be last. Many many years ago, when cheap mobile VR headsets were all the rage, some Chinese manufacturer ripped off the logo of our national rail company.
This is actually a good question if I'm answering it entirely based on feels, not actual data.
Biggest game overall, single player plus multiplayer? Halo series. Maybe Destiny 1&2 too.
Biggest PC game? Probably Neverwinter Nights (2002). (This predated Steam, so fuck the statistics anyway.)
Biggest game I'm spending shitloads of time right now? TRAIN SIM WORLD 3.