Machete

From the belly laughs of “Hot Tub Time Machine’’ to the body count of “The Expendables,’’ movies have lately been a feast of winking retro overkill. Just as the trendlet is getting tired, here’s Robert Rodriguez’s “Machete’’ to show us how it’s done: with wit, moviemaking skill, and a cast to die for. The movie’s an unexpected end-of-summer tonic: a trash guilty pleasure with a healthy (if really violent) sense of outrage. It’s also Rodriguez’s freest movie yet, and possibly his best.