SPOILER ALERT (DON'T READ THIS IF YOU HAVN'T SEEN THE FILM AND WANT TO):
This film is truly remarkable, from it's intriguing and complex underlying plot to it's memorable and emotionally driven characters; avengers endgame is truly the best superhero film to date (yes, better than the dark knight; in my opinion), and one of the best films I have ever seen (I have seen Citizen Kane, The godfather and other so called "masterpieces").
The end of Iron man and Captain America was very heartwarming and concluded their stories brilliantly, Thor was a great comedic fill in as well as a character we see struggling with self identity as well as regrets; and in the end he finds peace and companionship.
Some people wanted the Hulk to beat Thanos (as an act of revenge from what happened at the start of infinity war), but Thor did the whole revenge trope when he "went for the head" after the snap; and the Thanos the Hulk would've fought wouldn't have known about the fight.
I think nebula's story was more fleshed out in this film, and we saw it involved in the plot of the story, with her past self opening the quantum realm for Thanos and his army.
Hawkeye was more of an emotional character in this film, and we can see this when he tries to prevent Black Widow from sacrificing herself; This can also be seen when his family disappears. In the end; Doctor Strange's 'one in fourteen million' possibility starts to fall into place, with the film then comes full circle and Thanos getting SNAPPED by none other than Iron Man.
The only little nit pick I have was Stan Lee's cameo, I don't think anyone (including himself) expected him to die last year; so maybe for me it just didn't appear to be a very memorable cameo because he was probably expecting to appear in more marvel movies after avengers endgame.
I could go on and on about this film and all the amazing character portrayals, as well as Thanos and how he's a great villain, this film easily receives a well deserved A+ from me.
Stan Lee: "You know, I guess one person can make a difference" ;)