Definitely Quartz. It is indestructable. It is even better than granite. There is no maintainance with qurartz. You will be very happy.

I strongly recommend quart counters. We are using quartz in all of our current projects.

It really depends on the look. They are both fantastic products. I would stay away from corian in the darker colours due to the fact that if it does scratch it scratches white. Quartz is a lot stronger material but it is not repairable where Corian is. I like the high gloss finish of quartz but depending on the project the seamless nature of Corain may be a better fit.