1. A hoodie shows us you are relaxed and comfortable around us... not uptight or self-conscious.
2. A guy's hoodie is so much bigger and cozier than ours.  Room for two?
3. A guy's hoodie basically says, "I am good at cuddling."
4. A hoodie covers up any muscles that you may (or may not) have.  A little mystery is good.
5. A hoodie suggests that you could hold us by a bonfire and make s'mores.
6. Whether you're coming from the gym or the Burger King drive-thru, a hoodie makes you look more athletic.
7. A hoodie suggests you could take us camping... and fend off the bears.
8. When girls see a guy in a big, soft, cozy-looking hoodie, they get this instinct to go jump on his back.  Come on, I know I'm not the only one.
9. Your hoodie says something about you.... Abercrombie-type... On a sports team.... Obsessed with beer.... Or, maybe, that your mom buys all your clothes.
10. Your hoodie is a powerful tool... read my post on  "The Key to a Girl's Heart: Your Sweatshirt." 

Exceptions: Hoodies that are too short, too tight, have holes, or smell like your gym shoes.
My favorite look of all time: A hoodie, basketball shorts, and a baseball cap.  Sandals or athletic shoes... your pick.   Read more on this look here: "GUYS: Fashion Tips from a Girl's Perspective"!