Alright ladies and gents, let's get on the topic of what's on your head... What kind of hat or headwear do you prefer, and why?

I've been debating heavily lately to pick up a tilley, boonie, or outback oilskin hat. Something with a wider brim. I'm used to wearing ball cap style, but it's never the best in adverse weather or freak rain storms..

Let's hear your opinions and styles!