Their lives may be public, but they sure ain't perfect.
So it makes sense that stars, like the rest of us, might resolve to shape up and change their ways this new year. ABCNews.com reached out to experts in both celebrity hijinks and appropriate etiquette to find out who ought to start off 2009 with an attitude adjustment.
Below, see what Britney, Brad, Madonna, Miley and others should do to stay out of the tabloids and on top of Hollywood over the next 12 months.
Spears revealed her resolution to Us Weekly magazine: "I would like to stop worrying so much because I worry all the time. And to learn how to be happier, just in general. And to stop biting my nails!"
Howard Bragman, founder of Fifteen Minutes PR and author of "Where's My Fifteen Minutes?", thinks Britney should, "Keep on keeping on. She had a very good 2008. She didn't act out much. She had a successful album. I think she should just stick to her path."
Lizzie Post, great-great-granddaughter of etiquette guru Emily Post and author of "How Do You Work This Life Thing?": "She should go into '09 with her head held high. She's done a good job of turning her life around to some degree. If she tries to go after press ridiculously and pushes herself too hard, you can see how she might fall back into old patterns. Slow and steady wins the race."
Bragman: "She should resolve to have another year of proving her critics wrong. Everyone tells her annually, 'Oh, it's over,' and she always finds a way to reinvent herself. She came out with the No. 1 concert tour of the year again."
Post: "Now that her divorce [from Guy Ritchie] is final, the best thing she can do is consider their children and friends and try not to make anyone take sides. The more courteous and considerate they can be to people close to them, the better off their relationship or nonrelationship, as the case may be. I think she should try as hard as she can to keep out of the press for a while. Everyone loves pizza and a movie at home -- why not try that with A-Rod?"
Bragman: "Couple's counseling with her father. She and Samantha seem to be doing fine -- it's with her father that she has the problems."
Post: "Her biggest resolution last year was get off the drugs; this year it should be to stop fighting with her dad via the press. He is really throwing Lindsay's girlfriend under the bus and he has to stop speculating. The old adage about assumptions -- they're doing a good job of proving that one. It's just not flattering for either of them."
Bragman: "Her resolution for 2009 should be to make it to 2010."
Eliot Tiegel, author of "Overexposed: The Price of Fame": "Her life seems to be set in tragedy. The only way to change her life is for someone to take charge of it. It's not her parents, it's not her husband -- she needs someone who cares about this obviously talented woman to keep her on the path to sobriety."
Bragman: "Get over the breakup with Brad. Time to move on."
Post: "She's in a tough spot. But I would love to see a different topic headline in the grocery store. It's been four or five years that the paparazzi has gotten money off this breakup and it's enough. All three of the stars involved should put it to rest."