I recently came upon a great tumblr blog, called Mapstalgia.
Mapstalgia is a collection of hand-drawn maps of video game areas and locations. It's a really great nostalgic trip and the blog has a really great sense of community. All maps are user-submitted and allow for people to offer feedback and comments. These maps are really great conversation starters for old-school gamers.
The mantra of Mapstalgia is "Video game maps drawn from memory". The from memory part is very important. The charm of these maps is in their details, and especially in their flaws. This site is so cool, because it is all about memories.
If you're in the mood for having you mind blown, then I suggest checking out this post in which someone mapped out all of Half-Life from memory.
I was so inspired by Mapstalgia, that I even created and submitted my own map. With a submission, they ask you to include a little write-up, about the game and also about why you made it and what it was like (what did you remember, what couldn't you remember, etc). Hopefully, it'll appear on there soon, but in the meantime, here's a preview:
When you have some spare time, check out Mapstalgia, and browse through all of the maps. They're nicely organized by game, by genre and by platform. Hopefully, it'll stir up some fond memories, and you'll be inspired to contribute something, too.