Okay, forget about recent years where neither side has come particularly close to winning the title.
We want you to cast your minds back to the late 90s and early 00s.
In nine seasons between 1995/96 and 2003/04, there were just two Premier League champions - Man Utd or Arsenal.
And in most of those campaigns, it was a two-horse title race between the pair.
It led to some incredible battles with captains Roy Keane and Patrick Vieira often leading their sides into war.
But perhaps the most infamous clash between the two sides came during the 2004/05 season.
Arsenal had gone the entire 2003/04 unbeaten to become the Invincibles.
That run continued into the following campaign as they reached 49 Premier League games without losing.
But it ended in October 2004 when they travelled to Old Trafford. But that doesn’t tell the full story.
In fact, the whole story is told in a 10-minute video showing the shocking refereeing decisions during the match.
Now, we’re completely impartial. We don’t support Arsenal. We don’t hate Manchester United. But looking back at some of the decisions made that afternoon is absolutely crazy.
There is constant fouling of Jose Antonio Reyes. There’s Ruud van Nistelrooy’s horrific tackle on Ashley Cole. There’s Rio Ferdinand last-man foul on Freddie Ljungberg. There’s Wayne Rooney diving to win a penalty.
VIDEO: Arsenal 'cheated' out 50th unbeaten game vs Man Utd
Take a look:
In fact, the drama continued after the final whistle.
We’re talking about “Pizzagate.”
There was allegedly a tunnel fracas before the ‘battle of the buffet’ as Sir Alex Ferguson was reportedly hit by a flying pizza slice.
The culprit? Arsenal’s Cesc Fabregas.
In an episode of ‘A League Of Their Own,’ Fabregas was asked by host James Corden whether it was he who chucked a pizza at Fergie.
"Tonight, can we finally put the case of the flying pizza to bed once and for all? Were you the culprit that thew the pizza?" Corden asked.
"Yes," replied Fabregas.
"All of a sudden, I heard noises (from the tunnel) and I thought what's happening? So I go out with my slice of pizza and I saw Sol Campbell, Rio Ferdinand, Martin Keown... everyone pushing each other.
"I was like, I want to get in but I don't know how to and I threw... peeew... just threw it. Once I saw it was hitting, like, who it was hitting, which I didn't mean…"
Fabregas confirmed that it hit Ferguson in the face before added: "I apologise Sir Alex, really didn't mean to do that!"News Now - Sport News