Gears of War 3 map Bullet Marsh. Not because its shadiest corners house equally shady characters -- unless, of course, you consider maneating Kryll swarms shady. Which ... um, you might, now that we think about it.
Epic recently posted some information and a video flythrough of Bullet Marsh, one of the five free battlegrounds included in the Booster Map Pack, due out Thanksgiving Day. Check it out, and seriously, watch out for those swarms. Getting eaten by bugs is one of the worst ways to die in Gears 3, right behind getting chainsawed in half, curb-stomped and exploded.