Fallout 3: Mothership Zeta.
I'm kinda meh, so far with it. I just made my way to the cryo chambers, so it's getting interesting now. Funny side-note, I off-loaded pretty much all of my gear at my home, expecting to pick up a ton of gear like I did in The Pitt. I didn't want to have to decide between my wasteland gear and the new DLC gear, so I decided to go into Mothership Zeta with almost nothing on me. One or two useless guns, and all my ammo but no armor whatsoever.
But, after a while of running through the ship in my underwear, I looked up the list of armor...and it's zilch. So, I think I'll have to complete Mothership Zeta in my character's underwear now. That or steal someone's clothes.