One word: Unprecedented

Rating: 10/10 (13 August 2019)

I won't say much but this was the greatest movie theater experience I've had since Avatar. I see there's a lot of one star terrorists who would never be satisfied, or who only believe in arthouse type movies that are non-fiction. If that's you, then ignore this review. We'll both be better off.
The emotion, the tender love between characters who have been developed over the last 15 years, and just the general willingness to sacrifice everything for the greater good truly make the writing click in both infinity war and endgame. In addition, the writers were careful not to make it a requirement to see all 21 films leading up to this. Yeah, seeing infinity war and probably age of ultron is a must, and it will help you enjoy it more to remember some of the references from Thor: The Dark World, Captain America: The Winter Soldier, and the two Guardians of the Galaxy films, but generally, infinity war explains anything you may not now going into it.
As for the common complaint that 3 hours is too long, I will disagree. This is an end to a series on an unprecedented scale and it is totally worth your time.