Plywood - Plywood as a workbench top offers medium durability at a reasonable cost. Layer the wood so the top is a minimum of 3/4 inches thick and you'll have a sturdy surface to hold your projects. Plywood is also less likely to warp.
What can I use for a workbench top?
Almost any lumber or sheet good can be used to top a workbench. The main factors in choosing a bench top material are the function of the bench and the desired effect.