I've never heard that SIII are particularly prone to cracking screens .. Seems like a really good phone, particularly if you can get it for $100. Think I'd wait a month or so as I'm sure the price of the SIII will drop pretty quickly after the S4 is announced.
The high end HTCs are really good, too.
The Nexus 4 is awesome, but you should only get it if you're going to pay substantially less than they're asking for the SIII / One X.