Sylvester Stallone vs. Richard Gere
The two starred in the 1974 film The Lords of Flatbush together, but because they got along terribly, Richard's part had to be recast.
"We never hit it off," Sylvester said in 2006. "He would strut around in his oversized motorcycle jacket like he was the baddest knight at the round table."
The two later got into an actual fight over — true story — chicken grease.
"I was eating a hotdog and [Richard] climbs in with a half a chicken covered in mustard with grease nearly dripping out of the aluminum wrapper," Sylvester said in the same interview. "I said, 'That thing is going to drip all over the place.' He said, 'Don’t worry about it.' I said, 'If it gets on my pants you’re gonna know about it.' He proceeds to bite into the chicken and a small, greasy river of mustard lands on my thigh. I elbowed him in the side of the head and basically pushed him out of the car."
Today, the two still don't get along, with Sylvester even claiming that Richard accused him of starting the infamous gerbil rumor.