Maybe National Lampoon’s Vacation comedies, begun in 1983, hit your sweet spot. Maybe it’ll hit again with this next-generation reboot from writer-directors Jonathan Goldstein and John Francis Daley. With Ed Helms as Rusty Griswold — son of Clark (Chevy Chase) and Ellen (Beverly D’Angelo) — taking his wife, Debbie (Christina Applegate), and sons, James (Skyler Gisondo) and Kevin (Steele Stebbins), down holiday road, there must be raucous R-rated fun. You’d think, but the gags about pedophiles and eating shit smack of desperation. Leslie Mann and wild-card Chris Hemsworth, as her cock-flashing hubby, get the heartiest hoots. The rest is comic history warmed over.