And stayed engaged and involved when That Ending, that "They did WHAT?!" ending, happened. (Oh, and the end credit-scene revelation got a BIG pop from us.)
I've yet to not-enjoy, shall we say, any of the MCU films I've seen. Each is a strong combination of spectacle, wit, and soap opera, and before you say anything, I like soap operas. Infinity War, too. One of many lines that made me laugh very loudly was (and I'm taking this so out-of-context that it's not a spoiler) "An hour."
And at a key moment in the climax, I expected a joke. There wasn't one. This is, in fact, good.
So, late in the film, with fighting on two worlds happening simultaneously and one more Infinity Store for bad guy Thanos to get, Dr. Strange uses his powers to See The Future. He tells his fellow superheroes "I have seen 14.5 million possible outcomes of this fight." "How many where we win?" "I see only one." Which is why Strange then, um, does what he does, explaining, as much as he can, "It's the only way."
The joke I'd expected:
"I have seen 14.5 million possible outcomes of this fight." "How many where we win?" "Three."
See how that would have been deflating and wrong for the moment?
The moment needed to be huge and portentous. Whatever that "only way" is, we'll learn it a year from now.
And again, thank goodness the end-credits scene gave us a hint of what (and who's) coming.
Edited To Add: Also, saying that doesn't fit Dr. Strange's sense of humor, either.