I'd have to say Tenpenny tower, since I killed everyone (Even the ghouls you help get in there, and the rest of the citizens, except Godfrey and Shakes) opened the underground tunnel, and raided the shops of all their goods lol.
[color=#000099][size=48][b][font=Times New Roman]\"My hobbies, kicking a** and taking names!\"[/b][/color][/size][/font]