So my asthma is bad enough that laughing too hard is a risky prospect: it'll send me into coughing fits, which will in turn make it hard to breathe and, well, to live.
Deadpool 2 sent me into three of those. Once, "Oh, he's doing it! He's really doing it!" because my brother-in-law's son is learning to walk and those are the exact words that came from his wife's mouth. Once at the oft-parodied Pretty in Pink boombox moment. Once when it's revealed that the rest of the X-Men are just hiding from Deadpool while he's complaining about how empty the mansion is.
Frankly, though, I think the best moment overall was, "Seriously, your superpower is luck? How is that cinematic in any way! It's ridiculous!" while everything is going Domino's way as she storms the truck. Spreading her arms out wide and waiting for that inflatable bear to catch her... Domino is now my wife's favorite mutant.
Shatterstar dying was pretty awesome too.