What's one MCU trilogy you can watch without needing to see the other films to understand?

I've been thinking recently: What's one MCU trilogy that a typical non-Marvel fan can watch without getting confused? My first initial thought was Thor, until I realized they make lengthy references to other films that a non-regular Marvel fan wouldn't get. (Battle of New York, the short-lived Age of Ultron, etc). Then I thought Iron Man, but were it not for the huge gap of events between 2 and 3, it would make the cut. And then there's the Ant-Man trilogy... yeah, no, sorry...

The best examples I can think of are the GOTG and Captain America trilogies, which lightly glaze over the timeskips in between. But what's your opinion? What's the one MCU trilogy someone can watch without needing to binge everything else?