Topher Grace
Topher Grace is best known for playing Eric Foreman on That '70s Show, but his reputation certainly precedes him. After abruptly leaving the show before it was finished, the actor's co-stars called him rude and arrogant. Surprisingly, their words made an impact. Over the years, Grace has tried to turn things around, and he's slowly succeeding. These days, fans call him "a stand-up guy" and his co-stars only have nice things to say about him. Other celebs should learn from his behavior!
Carrie Underwood
Carrie Underwood is best known for winning American Idol back in 2005, which jump-started her career as a country superstar. Unfortunately, her sweetness might just be for show... Underwood has admitted that she can be quite selfish from time to time. She sometimes finds herself regretting not thanking people, or feeling bad about telling presenters not to goof up her entrance on television. At least she's aware of it, but the next step is actually improving as a person.