Nokia 920's in otterboxes are pretty damn indestructible. Even without the otterbox they are pretty unbreakable.
I can vouch for this, the gf has one and it's dropped several times a day and has already fallen into the toilet fully submerged once.
It's not sold as a "rugged" phone but it's stronger then some of the phones rated as "rugged".
Windows Phone 8 has an amazingly clean UI that's fast and simple.