Lets talk about celebrities who behave admirably, who do something worthwhile with their status.

Rule: Whatever good thing they do can't be the main reason they are famous. Jonas Salk was very famous for curing polio, so he wouldn't count.

Brad Pitt-

Despite seeming the biggest douche on Earth for his Chanel #5 commercials, I admire that he throws his effort and celebrity into his non-profit "Make It Right" organization to rebuild New Orleans with quality green housing. An odd choice for a dude who supposedly loves Ayn Rand, but still, good for him.