What DC/Marvel crossovers are canon?

[Slimybug]

What part are you referring to? All I remember is that they reference a panel from JLA/Avengers at the end of the video to explain how the Infinity Gauntlet doesn't work outside its home universe, but they don't say whether its canon or not. When actually explaining why it doesn't work, though, they refer to Hickman's FF.

It's actually only in text, at 25 minutes.

[Lonewolf36]

Marvel considers pretty much all crossovers cannon as referenced in character's histories in Marvel Handbooks. Mantis handbook entry even mentions her time as Willow on the DC Pre-Crisis Earth an encountering the League. I think Living Tribunal's and Grandmaster's entries mentions JLA/Avengers they just cant uses name so Justice League becomes a League of Justice an so on. Access co created by Marvel and DC for the crossovers appears in an issue of Green Lantern his only appearance outside the crossovers. The Cosmic Egg form the JLA/Avengers is a major plot point in the 52 issue weekly Trinity series by Kurt Busiek. Extreme Justice has Blue Beetle using ball webbing he got the idea from a character from another dimension. There are plenty more but those come to mind at the moment.

Others events of Teen Titans/X-Men is referenced in an issue of Showcase from DC. The Brothers from Marvel Vs DC is seen and referenced in the Adventures of the X-Men comic.

[Jackalope89]

Since Flashpoint? Not sure. Though in Superman Rebirth, when Booster Gold helped out Supes, he did mention Iron Man/Jarvis.

[Green Goblin of Sector 2814]

It's actually only in text, at 25 minutes.

Okay, yeah, I saw it. They're talking about JLA/Avengers when Darkseid puts on the Infinity Gauntlet. But the thing is, I don't know if they're actually correct when they say its technically canon. It still might not be. The fight remains unchanged, of course, because the Infinity Gauntlet not working outside its home universe is well-established in the Marvel universe itself.