While tartans are arguably the most familiar checks to most individuals, Glen check is likely the most common for suits.
This check, often called Prince of Wales check, resembles a tartan, though it is primarily monochromatic. It utilizes bands of vertical and horizontal stripes which, when viewed as a unit, create a wider check effect in the fabric.
Glen check has deep associations with the country and weekend wear – having been created for use by English nobles in Scotland who lacked a family tartan – though it is appropriate for most semi-formal occasions. It may be frowned upon in certain professions with a particularly strict dress code but should be acceptable if not welcome divergence for most men & women.