I'll usually play a fighter when I get burned out running casters. There's something satisfying about just picking up a weapon and simply wading into combat. Not having to worry about spell selections or crafting magic items is its own reward. You also have more time to dictate camp layouts, party formations, and big picture concerns (like what are the group's goals). Not that a caster can't do any of those things but non-casters are less likely to be sequestered with magic-related tasks.