One of the more obscure classic PC games (VERY long, and pretty good) is Darkspyre II: The Summoning.

http://www.jaelus.com/thesummoning/right.htm

I am not certain whether or not this can be downloaded from the Underdogs.

EDIT: Looks like it is available, and it looks like The Underdogs is back in business.

http://209.120.136.195/game.php?id=1087