I use a vernier caliper by Mitutoyo, Japan, and a micrometer by Limit, Sweden. Both are great and work very well. Mitutoyo's F&F are exceptional. I use the micrometer to measure the thickness behind the edge.
I picked up a few cheap 8" calipers on ebay, lost 1/3 pretty quick, have to see how long the other ones hold up. Maybe getting a quality one IS cheaper, but I don't need ultra precision. What I find extremely helpful is if you can switsh from real measures (mm) to awkward measures (inch fractions)