This movie is very fun to watch. Super-power team up attacks are fun. Pietro making fun of people for being slow and suffering hubris is fun. Quick, little, not so secret ending that occurred early on in the credits was fun. James Spader is fun. So many times I found myself saying, "Captain America is so cool!" or "Hell yeah, no way Hawkeye would have anymore of that mess!"
I loved seeing more of Hawkeye and all these quiet moments between Bruce and Natasha. There is just so much in this movie, with a great and fun party scene in the beginning, Chekov's guns laying about all over the place. Running jokes and references. It is simply and amazingly fun to watch.