Pretty much what the title suggests. What do you think is the best MCU trilogy?
We've had 6 so far - Iron Man, Captain America, Thor, Ant-Man, Guardians of the Galaxy, and Avengers (I'm counting Infinity War and Endgame as two parts of the same movie).
I suppose there's also a discussion to be had about whether any of these count as 'trilogies' in the classic sense since not one of them is unaffected in major ways by intervening films. GOTG is the closest to being a trilogy you can watch without watching the other films and still (mostly) have it make sense - gotta love how Gunn explains the post-IF/Endgame Gamora situation
Anyway, recency bias tempts me to pick GOTG, and I have a feeling many will go for that, but I'll actually go for Captain America. None of these trilogies are a hat-trick of perfect films, but Captain America IMO comes closest. The First Avenger is a pretty solid outing, and The Winter Soldier and Civil War are both among the best MCU movies.
With GOTG, Vol 1 and 3 are both great and among the best MCU movies, but Vol 2 honestly, while a decent film, didn't particularly excite me and was overall a mid-level entry.
As for the rest - I think all the Ant-Man films were pretty good, but nothing great. IM1 is legendary and 3 was great but 2 was okay-ish (I still love it though for old time's sake). Of the first three Thor films, only Ragnarock is truly great - the first one was a solid outing but nothing spectacular and The Dark World is possibly the single worst MCU film (I think Love & Thunder at least has far more entertainment potential!) And with the Avengers, Age of Ultron is a decent outing but nothing mind-blowing, and over time you realize that while the first film has a place in cinematic history for being the first major superhero crossover/team-up film, as a film it's really not in the same league as some of the MCU's finest.