Not sure if I can narrow it down to just one year but if I was going to pick an era for best PC games I'd say 1998-2002ish. SMAC, Starcraft, Deus Ex, Morrowind, all soooorts of good stuff. Actually seeing as those are my four favorite games of all time, well.

For console games I'd probably go with mid-90s? But that might be the nostalgia talking.