My five favorite stars are:
1. "Weird Al" Yankovic: I am a big fan of his mix of professionalism, creativity, seriousness about the quality of his work, and humor. And he remains hugely approachable in person.
2. Steve Martin: I am a big fan of "multi-talented" as an attribute. Steve is obviously a brilliant comic, and his numerous hosting stints on SNL are the stuff of legend. Add to that his writing -- including screenplays (e.g., Roxanne), novellas (e.g., Shopgirl), essays (e.g., Pure Drivel), and plays (e.g., Picasso at the Lapin Agile), and you have the makings of a very cool, very funny man.
3. Tom Hanks: I mean, he's an obvious choice for sure. But he just seems so friendly and cordial. He doesn't have the Brad Pitt or even David Schwimmer syndrome where you can read an interview with the celebrity and then realize that he's kind of a crappy person. He comes off as a good guy. He's very funny -- and again, always excellent on SNL -- and I'm a big fan of his first self-written motion picture, That Thing You Do!
4. Jeff Goldblum: He's really good. I mean, he's really, really good. He's an excellent actor and has a delightful sense of humor, in that it is nearly exactly like mine.
5. [tie] Michael J. Fox and Will Ferrell: Certainly these are two very different actors. Michael I like because of his excellent timing (just check any of the Back to the Futures to see what I mean); Will I like because of his excellent delivery. Michael has fought his current, ongoing battle with Parkinson's gracefully, so that gets him bonus points as well. And we all watched Will transform from nobody on SNL to a huge movie star, which I perceive him as having done with humility. So, I like them.
PS: I also like some female stars and celebrities, too ;)