Ultimately, the right muzzle device for your rifle depends on what you intend to use it for and your personal needs and preferences. If you're looking for an addition to a gun intended for self-defense, a flash hider could serve you well.
As a competitive shooter, you may be looking for a muzzle device that helps you stay on target better or allows you to practice for longer. In these cases, a compensator or muzzle brake may be the right choice. As with any accessory you add to your firearms, the goal is to maintain safety and improve your ability to hit your target.