The Whole Gang's Here

 is an achievement in Fallout: New Vegas which is awarded for successfully convincing all of the companions to join you.

Bugs

 * This achievement is apparently bugged and instead of hiring all of the companions, all you need to do is hire/rehire any companion as many times as there is companions. (May not work on all systems)
 * Instead of hiring all companions, it may unlock simply by meeting all them and not hiring any.