Should I choose a matte or gloss finish for kitchen counters?

For kitchen counters go with a matte finish. Gloss finishes are suitable for vanity (Bathroom) counters but not kitchens. This is not a firm rule but there is good reasoning behind it.

Matte finish laminates withstand use and abuse without showing it much better than gloss laminates do. It just makes sense - Gloss finish laminates are still made of the same tough materials, but when the light hits that little scratch just right, it sticks out like a sore thumb.

Not only is "Not using gloss laminates for kitchen counters" not a firm rule, it is a rule that has been broken countless times over past decades that have seen plastic laminates reign supreme in the kitchen. Indeed there was a time when Formica manufactured miles and miles of gloss white laminate with shiny gold flakes embedded in it, remember that? That gold flecked creative masterpiece found its way into more kitchens than..., well it was installed in a heck of a lot of kitchens across the nation. 

The point is that while many people have been perfectly happy putting gloss finishes on heavy use counters, if you can go either way, go with a matte finish.

Although not specific to kitchen counters, gloss finish laminates also tend to telegraph much more than matte finishes. If you're prone to have strong opinions about small visual defects, expect to have opinions about the small waves or bumps (And they will be small if the counter is professionally manufactured and installed) that will be visible on gloss finishes due to imperfections in the substrate or gluing process.