I can't remember which of the Iron Man trailers I saw. I just went to see it because I'd always loved Iron Man (up until the comics went off the rails in the late '90s). I had fan-cast several people as Tony Stark over the years. Never RDJ. I didn't have high hopes... But higher than I'd had for the Fantastic Four movies or, really, anything since X-Men III dropped the ball. I was gobsmacked.
Since then? I gave Incredible Hulk a pass because I erroneously thought it was a sequel to the Eric Bana Hulk film. Never even watched a trailer. Then Iron Man 2, so of course I saw that one. Thor, Cap, Avengers -- hell yeah I was along for the ride.
Unlike some on here, I love Iron Man 3 and Dark World, as well as Winter Soldier. I like Age of Ultron a lot, in spite of its flaws. Which, as with Iron Mans 2 and 3, are chiefly that each should have been two films (escalation of cornerstone stories should have been a thing -- as the scope of the macro-story expands, so, too, needs the run-time to tell it: as AoU should have been two films, the Infinity Gauntlet story should have been three).
Guardians of the Galaxy, Ant-Man, Doctor Strange, and Black Panther I was all sooooooper skeptical about. Guardians was weird and had such a rotating roster I knew it was going to be a mess. Hank Pym is an abusive ass and I couldn't see a movie about him being remotely interesting. I had zero faith in Marvel's ability to depict the mystical side of things on the big screen. And there was no way I could see them making T'Challa and Wakanda compelling. And Spider-Man? I was actually mad at them for recasting Peter Parker yet again. I liked Andrew Garfield, dammit. How could they do better?
By now I have seen how many on here feel about all of those movies. I agree with some of you on some things, and some of you on other things. But I haven't hated, or even strongly disliked, any of the movies or streaming series (including the now-defunct Netflix series). I have issues still with some casting choices or story choices or pacing choices, but, in the end, I'll sit down and re-watch Dark World over many other options. So my takeaway is generally no real urge to watch the trailer, because I know I'm going to see it. Each time I've doubted -- based on the trailer or subject matter or actor, I've been wrong. Each time I've been overexcited about some installment, it's done something to disappoint. No, Marvel aren't perfect, but they are pretty ******* good and I trust them, regardless of what's in the trailers.
Which, by the way, I have watched, though it was someone else showing it to me. It didn't tell me anything I didn't already know about the Eternals. I expect a lot of what was in the teaser will be in the first forty-five minutes of screen time -- their arrival and what they've done down through the centuries, etc. Very, very little seemed to involve the here-and-now. Most notably the stinger at the very end, which made us all laugh, because we know the lore.
I really couldn't agree any more!