Lighthearted and fun, the movie was “Grease” for a new generation, and kids (and kids-at-heart) ate it up.The franchise spawned two sequels, the last of which was released in theaters and still holds the record for biggest opening weekend box-office for a musical, earning more than million worldwide.Gossip columns claimed he had actually fallen on a glass coffee table after partying. Things are good.” It appears he’s cleaned up, having taken time to reflect.When “Today” asked him about rehab last week, he dodged the question: “I’m in the best place I’ve ever been . “In the old [Hollywood] days, fame was kind of cool because clearly it was earned,” Efron says.But, as with so many twentysomethings trying to figure it all out, things didn’t go quite as planned. Efron and Hudgens are both returning with intriguing projects.In 2010, the pair broke up and took on critically reviled movies like “Charlie St. Scandals arose left and right — nude photo leaks (her), drug rehab (him). Hudgens, 25, stars in the gritty drama “Gimme Shelter,” in theaters now, for which she transformed herself by chopping off her hair and gaining 15 pounds to play a 16-year-old pregnant runaway.