One of the greatest games I ever played that led to the world of grafic adventures was Maniac Mansion on my beloved C64
(rest in peace ... until I start CCS64 again
A few years ago some MM fans started to create http://www.maniac-mansion-mania.de
Different creators started a game with different seasons each consisting of 10 episodes and even differnt special (Halloween 2005/2006 and others).
All together are about 80-90 parts till now and the developement on new adventures is still going on.
If you want to create new stories on your own, you´ll get a lot of places, animations and gfx at the resources - so you can quickly start the fun!
Of course the stories are extremely different, sometimes with following plots or continued stories connecting on former parts. The grafics are in most cases better than the original games and the stories are sometimes totally crazy. You have to solve mysteries, fight against flesh eating zombies, find killers, explore deep dungeons, fight against the meteor again, escape from edna´s love, attend crazy experiments, manage blind dates and make many many more funny adventures. You play a huge variation of figures like the meteor police, Bernard, tentacles, Ed, Dr. Fred, Britney, Syd, Dave, Sandy, Razor, Inspector Clouso, Hoagie, Jeff, Michael and other new characters at different places, times, parallel-universes and dreams with several sidekicks at other games like Zak Mc Kracken and monkey island. Some of the games are now translated to english: http://www.maniac-ma...ia.de/international/
There´s a really huge Maniac Mansion galaxy to explore (especially if you understand german