Miranda Lambert

On the caution-vs.-candor scale, it's not hard to figure out where Miranda Lambert comes down. "I'm really not careful at all," she says. "I probably should be. I pretty much don't have anything to hide, though. I never hid anything growing up. My parents were PIs, so I really couldn't."

The 25-year-old star's biggest hits have tended to be her boldest songs, so she's not about to put a lid on her plain-spokenness now.