The Legend of Zelda.

[Nightspade]

This is the game franchise that defined so many others. Now, a new addition to the series is coming out, Twilight Princess, quite possibly the darkest game in the series.

Here's the basic break down:

A dark fog is spreading across the Kingdom of Hyrule. This fog is, in fact, the 'gate' to the Twilight Realm, a bleak and dark place filled with peril. Every time Link enters the realm, he is changed from man to beastly wolf... Can he save the kingdom from the Twilight?

[bigpenguin]

I'm not a fan of Zelda personally but that does look like a good game. And having a darker theme should make the game better.