I'm one of the few who likes the second one better, to the point where it's quite possibly one of my top three favorite MCU movies.
Come to think of it, a lot of trilogies seem to follow the formula of really good to great first movie, even better second movie, mediocre third movie (Nolan Batman, Raimi Spiderman, Kung Fu Panda, both X-Men trilogies off the top of my head, I know plenty who feel that way about OT Star Wars and Evil Dead, though in both cases I think three is better than one).