If you are looking for a tough dirt orented dual sport, consider the DR-Z. I am more impressed the more I ride mine and hear about them the more impressed I am. I have heard of them being dropped off vehicls going down the Freeway and being rideable. Last summer I broke a radiater and rode mine back to camp running out of water on the way. No problem. Today I ran accross a thread on advrider whare a guy didn't realize he lost all his water and rode it over 50 miles with no engine damage.
If you want a dirt orented dual sport think about the DR-Z. There may be others with more power etc etc, but no other is as tough as these things IMHO.