yeah, hero's quest and QfG2 are my all time favorites, and the space quests are up there too. Not just for the nostalgia, they can still hold my attention better than most, even with the text parser and lack of pretty graphics. QfG4 rocked too, despite the buggyness.
And of course Sam and Max, MI, Grim Fandango, and the dig are all up there, but they never meant as much to me.