Corian is on the outs partly because it looks too plasticky. It's
also too easy to scratch, despite it's alleged renewability.

Granite has to be sealed, so that has opened up a market for
engineered stone like quartz composites. They don't stain, and many
varieties look very much like natural stone. The more natural it
looks, the less likely it's going to look faddish in the future, in my
opinion.

Stainless is an expensive workhorse that shows scratches. Some
complain that it looks too sterile or industrial. Concrete seems too
prone to cracking to be ready for prime time. It also needs to be
sealed to prevent stains.