(hopefully with this being the spoiler thread it's a given that this will all be massive spoilers so won't need tagged)
I loved it, and was really taken by surprise by how emotionally invested I was in the whole thing. I mean, I've watched every film and enjoyed them all (loved some and merely liked others but they've all been fun), but for some reason going into this I really didn't expect it to hit me the way it did.
There were plenty of moments that had huge (and quite unexpected) emotional weight for me - I got pretty sniffly at Stark's sacrifice and welled up when he hugged Spidey - but the moment that actually made me cry was when everyone appeared for the final battle and Cap gave his 'Avengers...assemble' line. It probably wasn't the most unexpected scene in the world but seeing that and hearing that line it hit me so damn hard just how cool a cinematic thing this whole ride has been, and I was completely taken by surprise by how much weight there was in that moment for me. Had no idea I was so invested in the whole thing to be honest, it really snuck up on me! Goosebumps just thinking about it now.
It's genuinely an incredible accomplishment to have run all these threads and characters through so many movies over so many years and then to have it all come together in a finale as confident and great as Endgame blew my mind a fair bit.
Had very few quibbles with it, in fact I think my only one was that I spent probably a couple of hours of it wondering where Captain Marvel was and if I'd missed some explanation for her not being involved until she conveniently appeared in the final battle. I vaguely recall during the hologram conference call her saying she was heading off to do something but I mustn't have registered what that was. Was she going to bring in more reinforcements (the goody ships that joined the fight maybe)? I'm sure it is just me missing something but it felt really strange to have her set up as such a great character and then have her missing for so much of it. I loved her new hair, she looked very cool.
As others mentioned, the moment when every female character appears to back her up did feel a bit forced and cheesy to me, BUT it was also incredibly badass and cool enough to see them all come together that I was glad it happened. Plus although I did a partial eye roll at how unlikely and slightly silly it is that all those characters would converge on the same spot of the massive battlefield at the same time, I quickly thought about the small portion of the fanbase who will be livid about it and was immediately okay with its inclusion. Yes it felt a bit obvious and forced, but as a clear statement about just how little those particular toxic fans' rantings actually mattered to the film-makers I thought it was brilliant.
The length didn't bother me (I somehow managed to get by on a single quick loo break!) and we were talking on the walk home about how in years to come Infinity War/Endgame will become one of those things we probably bring out on the occasional rainy Sunday when blankets and an epic film are all you want.
I've seen a few people saying that seeing it in a busy screening really added to the experience, I wish it had in mine - the constantly rustling bags, phones, the chorus of watch alarms at the top of every hour, the really young kid in front of me who got restless and agitated early on (not her fault, definitely got the impression the cinema trip was for the parents and the older kid and she'd just been dragged along!)...none of that spoiled the experience as such but it definitely didn't add anything at all. If the movie wasn't likely to be spoiled for me I would have preferred to wait a couple of weeks until things quietened down, but that's the compromise you make to see a film like this on opening weekend so I knew what I was getting into and was fine with that!
That was a lot of ramblings, short version is I loved the film, and on a level that I didn't expect and in ways that I think will make rewatching all the movies again (which I'm currently very tempted to do) a very rich and rewarding experience.
