I'd probably be safe in saying that my flip phone is tougher than any smart phone on the market today. it's survived 2 car accidents, going through the wash, going through a water park. getting tossed about for the past several years, and bouncing down the road after being dropped while I was doing 50.
Samsung SPH-A580 Specs, Features (Phone Scoop)
EDIT : and that was all without a case or any aftermarket protection.