I'm in my 40's now and I don't know why, but most of my fond memories of gaming came from playing games like Dan Dare, Beach Head, Raid Over Moscow, Paradroid 90, Monty Mole & Shadow Of The Beast, Wizball, Goal, Sanction, Uridium etc on the C64 & Amiga. Looking back, yes the games are simplistic in comparison to today's games, but maybe they left more to the imagination and that's why I enjoyed them so much and have such fond memories of them.
My only real fond memories of PC gaming are the Half Life series and Far Cry and now maybe it's time to hang up my joy pad and mouse and retire, as I'm getting too old for games.