Legerdemain, to me, was the least conventional roguelike setting I've ever played. It seemed like a giant crazy mishmash of psychedelia and decay, and was a mostly original piece (aside from the orcs... why on earth he decided to include orcs, I have no idea.)
Sil is based on Tolkien's, uh, obscure fairy tales surrounding the ancient times of gods and demons, back when the world was still young. Sort of a clash of the titans, Lud-in-the-Mist type of thing. It's nice and consistent, and come on, it recites poetry to you when you start up the game.
If you invest a little into smithing, you can create a lesser gem, which lasts forever and casts as much light as a torch. However, with Sil, the limited light resource is not your biggest concern, nor is food. If you check your character's stats, you will see your current dungeon depth next to the "minimum" dungeon depth. Morgoth's darkened halls sing out and draw heroes ever deeper...
Anyway, hope you like it. I love solid themes in my video games and think that Sil does a great job here.