My mounted jackelope head and Camel Cigarettes lamp
You sir, have excellent taste.
I have a love of cartography, so before it was my son's nursery, I had the walls of my 'office' adorned with various maps. Ancient maps of the world, NASA imagery maps of the world, maps of Mars and the Moon, a map of the Graveyard of the Atlantic, travel maps of cities I've spent time in such as Prague, Beijing, Shanghai, Adelaide, etc.
I never quite understood the "sexy chick" poster thing. True, for some bizarre reason my first two posters that adorned my room at home when I was a teen were posters of Cindy Crawford and Kathy Ireland. I'm not even sure why, and I think my folks were fine with it simply because it was some evidence that I was actually interested in the opposite sex. But those went in the trashcan when I moved to college, and pretty much nobody in my dorm had those kind of posters. But then we were the special dorm composed mostly of bright social misfits. On the rare occasions when I visited "normal" dorms, those and beer-related posters were pretty much
de rigeur.
I think at some level, at least in college, it's a peer pressure thing and a cheap and easy form of group ID.
"I am a young male who is interested in sex and alcohol!"
"Yes, I too am a a young male who is interested in those things."
"Let us be friends, since we are interested in the same things...and are forced by necessity to live together in cramped quarters for the next several months."