I would say it depends on what industry you want to go into. A lot of aviation, for example, use Catia (Boeing, Cessna, Beechcraft, etc).
My company uses NX4, which I and all my coworkers hate (a lot of the hatred is because of how the company has it setup on the networks, it takes 15 minutes just to open). But as others have said, once you know one package it should be pretty easy to learn a new one.