I just finished playing Point Lookout, the new DLC for Fallout 3. Set in a post-apocalyptic version of the actual Point Lookout State Park in Maryland, the DLC sends your character on a main quest involving a missing girl and a crazy fruit-worshipping tribe. There are also about five side quests, including a hilarious one involving a failed Chinese spy mission. Story-wise, this has nowhere near the epic feel of the last DLC, Broken Steel, but it does compare favorably to Operation: Anchorage or The Pitt.
Point Lookout is fairly big, and there's a lot to do and explore besides the main quest. Along with some familiar adversaries, the primary new enemies in the map are the Swampfolk, who look like mutated hillbillies. They're quite scary-looking and reasonably tough. There are also, as usual, several new weapons, including the axe, lever-action rifle, double-barreled shotgun, bio-canister grenades, and the microwave gun.
If you have 800 Microsoft points burning a hole in your digital wallet, this is worth playing. At the very least, it'll provide a Fallout fix until Mothership Zeta comes out.