Prost v Senna, Schumacher v Hill, Alonso v Hamilton - just a handful of motor racing rivalries that have gone further than the usual sporting 'misunderstandings'.
But those guys have got nothing on the world of NASCAR where, as the video shows, the latest feud ended up in a flying crash at 180mph after a deliberate retaliatory tap.
At the Atlanta Motor Speedway last weekend, Carl Edwards was running 156 laps down in the Kobalt Tools 500, so you'd think he wouldn't be concerned about putting in too much effort with seven laps to go. Not so.
Perhaps still smarting from a huge collision last April at Talladega Superspeedway when Keselowski hit him from behind, launching his car into the fencing and injuring seven fans, Edwards saw fit to return the favour 11 months later. Well, revenge is a dish best served cold.
Edwards turned his Ford into Keselowski's sixth-placed Dodge at Atlanta, a move that launched Keselowski into the air and flipped his car which then crashed roof first into the outside wall.
Even by NASCAR standards this was an horrific crash and Keselowski was fortunate to walk away unscathed.
Meanwhile, Edwards showed little remorse for his actions (his hands were clearly visible on the steering wheel turning right into the Dodge), and said: "The scary part is that the car went airborne, which was not at all what I expected." Oh, Well that's all right then.
Here's the previous incident that may have started the whole feud