I am addicted to games and cant stop playing a game once I start it no matter how tedius and boring that might turn out to be(and that's without any cheat-codes). I have played both deus ex and oni and finished both of them. However, i dont see any reason for these two games to be in the "The BEST PC games of all time". They both are "mediocre"- categary games and got tedius as i played along. My list would be:

Nox
Diablo 2
Unreal Tournament
Hitman
Warcraft 3
Age of Empires 2
Return to castle wolfenstein
Grand Theft Auto(GTA) 3
Medal of Honour
Soul Reaver 2
.... and many more

I have played almost any games u can name
But becos i m running low on cash for the last 1 and a half year my pc has become quite obsolete compared to today's high-end graphics machine and i have to say with a heavy heart that i havent played most of the latest games and probably wont any sooner bcos my pc wont support it. I am getting detached with all the best games of recent times