Girls have so many more choices than guys do when it comes to clothing options. For guys it's a combination of some kind of shirt, pants, and jacket.
Anway I wear a lot of different styles depending on my mood (I can clean up 'good' when I want to), but there are a few things I simply won't wear, Behold!:
Poorly cut loose fitting jeans (I like my jeans to feel like a glove for my ass)
Spandex (no explanation required)
Oversized T-shirts (I like my shirts fitted)
Khakis (If I want to clad my lower half in formal attire I go with a pair of pin striped suit pants)
High waisted pants (I love low rise jeans, but I'll make an exception for suit pants, low rise just doesn't work with a suit).
Golf Shirts (not my scene)
Boxers (I like to keep my stuff in place)
Turtlenecks (though I own a pseudoturtleneck that's open in the front and the collar can be folded down)
Neon colours (no dice!)
Sneakers (I love my biker boots, but when those are a no go it's dress shoes, an exception is if I'm working out or doing something physical outside).