Our company offered me a choice between a Mac and a PC, but also said that the former is heavily recommended so I picked that option. I didn't want to be the guy who constantly cries for help because stuff is just not designed and never tested on windows.
Don't forget the constant peer pressure and lame jokes from your coworkers! Oh and if you're a Mac newbie, be prepared to figure it out for yourself. Not that people are unhelpful but that they genuinely don't know any other workflows beyond their cloistered little OS with a barely-usable kernel.
