“Popstar: Never Stop Never Stopping” (***1/2 out of four) was a hilarious parody of the hip-hop and rock industry about a former boy band member turned superstar solo artist (Andy Samberg) whose latest album is a flop and who tries desperately to hold onto his fame, even if that means eventually later reuniting with his former group. Slick and fast-paced comedy features sharp writing, a great lead performance by Samberg as the clueless star, and very funny cameos from Nas, Usher, 50 Cent, and Method Man (among many others). One could call this a rap version of “This Is Spinal Tap” but one could also call it one of the funniest and most entertaining surprises of the year.