Back in the late 80′s and early 90′s, I spent many hours as a young shaver playing the fabled games of Sierra On-Line such as Space Quest, Kings Quest, and yes, even Leisure Suit Larry (any versions since 1996 or so do not really capture any of the classic elements of that game). There are definitely some good games out now, but I still think my favorite all time game series would be playing the role of Roger Wilco, a janitor turned superhero, in SpaceQuest.
I think one of the main reasons these games were so fun was because they were so humorous. Modern games really do not compare at all, as they have to have a lot of bling-bling to keep the kids interested.
Apparently the CEO of Sierra On-Line during the period which it actually put out games has a fan site up, and actually answers questions in the forums from time to time. Good stuff!