Hmm...I don't usually play games like that these days...although my dad, brother and I spent most of our waking hours on King's Quest:MoE years ago...good times.
In terms of free stuff, I've frequently promoted Abandonia.com
in this forum; there are a lot of old school games there to try out. Abandonia's cousin, Abandonia Reloaded
, has some fan made original games that are worth a look.
However, I also recommend that you read the Full Free Computer Games
thread as well...it has a ton of links to other websites with some good games, as well as suggestions by other members here. You're bound to find something that you like.