Last time I built an underground base with a bedroom, a mine, and an entrance with stairs.
Perfect for collecting mob drops because I leave one door open on my entrance and close every other door, so that they will come through the entrance but can't get into my bedroom, and if I leave the door open the light will set the skeletons on fire which are just about the only things that can hurt me because of their arrows.
How about you?
PS. I did not make that Herobrine account, some troll made it to freak us out, but he totally phailed.