Bobby Farrelly

Bobby Farrelly -- who's made some hilarious films, and also "Dumb and Dumber To" -- was busted for DUI ... TMZ has learned. According to legal docs, obtained by TMZ, the 61-year-old famed director was pulled over around 2 AM in Ketchum, Idaho after cops say they saw him driving without taillights…

The guy who directed "Dumb and Dumber," "Something About Mary," and a ton of other legendary comedies was arrested for allegedly attacking a couple of police officers. Bobby Farrelly -- of the famous Farrelly Brothers movie team -- was popped in Stowe, Vermont earlier this month after cops say he…