Oh my son and I rewatch a lot of the Marvel movies, we have them all on Blu-ray. Guess it's something kids do and it's nice to watch them together. I remember as a kid recording movies off the TV and watching them over and over. Terminator 2, Aliens, White Men Can't Jump etc.
I'd say the most rewatchable for us in the MCU in no particular order are Infinity War, Thor Ragnorak, Civil War, Black Panther and Guardians of the Galaxy 2 (he is going to watch the 1st one this weekend with me for the first time so I'd say this will be added).