#5 Martinsville 2010
It's no secret that Kyle Busch isn't the kind of man to mess around with on the track, and Jimmie Johnson found that out the hard way during a 2010 race at Martinsville. The story goes like this: Johnson and Busch were racing hard for position early in the race- not a good idea. This is because it encourages payback later and can also lead to wrecked race cars if taken too far. While Busch versus Johnson didn't come to this, it did get pretty heated.
Now, a lot of that has to do with Johnson's refusal to give up his position even though Busch's car was faster. This eventually led to Busch coming over the radio and telling his team," Why don't you go tell the #48 I wouldn't be beating his expletive bumper if he would have let me go 40 expletive laps ago, asshole. Stop flipping me off and just drive your expletive, you little expletive."