I don't have to wear one but I like to for protection and shade.

I have a Bell Pit Boss half helmet, a Bilt Roadster 3/4 helmet and a Scorpion Exo 500 full face helmet. Weather and mood are my deciding factors when I leave the house.

I like the Pit Boss for the adjustability and it has ear muffs for the cold. In an emergency the flip down eye protection is nice, but I usually wear sunglasses anyway.

I got the Bilt (Cycle Gear brand) 3/4 helmet for my daily commute. I like the way it looks and it offers more face protection for flying debris on the freeway. The mirror shield I added looks cool too.

I got the Scorpion Exo 500 because I thought it was a good bang for the buck helmet. It's great for cold/rainy weather, but I can't drink anything while riding so I don't wear it much. Oh, and it has skulls on it.

I would love to get a Shoei Neotec in the future.