A Tale of Two Kingdoms, the one I recommended in that thread, came from Adventure Game Studio
It's always been a good place to look for free games.
The Shivah used to be free there (good game, I enjoyed it) and I downloaded all of the Ben Jordan games from AGS.
Browse through, read the descriptions and the comments.
(She may not be everyone's cup of tea but I enjoyed the murderous Emily Enough and Earl Bobby Is Looking for His Shoes is totally a hoot.)
You are bound to find something you enjoy!
Oo! Oo! Forgot to mention! Bog's Adventures in the Underworld
is a Great game.
It is very, very long and very, very convoluted and Bog has to be the most unusual AG hero ever.
If you like chess (or even if you don't), Wretched
also has a free game called Zugzwang that teaches you how to play using a sweet, white pawn and an evil red one. Heh, heh.