That is pretty cool.
But I will not fall for your bribery. XD I did not like Avengers much. A good popcorn flick that I have no intention of watching again. If Downey Jr. was not in that movie, it would have been so boring. He carried it. I did not feel invested in any of the characters or what was going on. I did not care. It was like watching a very expensive episode of Power Rangers.
That's fine, I felt invested enough for the both of us, and about twelve other people :P
The characters were the strongest point of the movie. I cared about each and every one of them (even Thor, who I was not expecting to like) and the most rewarding part of it was watching their interactions and the challenging dynamic within the group. Joss Whedon has this gift to make every character real and human, even in such ridiculous circumstances as you'd find in a comic book movie. Black Widow, for instance, was a bit bland as a character in
Iron Man 2 because she was basically there to fill in time and do some cool stunts, but in
The Avengers she was given a far richer character and held her own among a cast of characters just as strong as hers.
There's no question that Robert Downey Jr. was one of the best parts; but he was always going to be. There was simply no way around it. His character had been established in its own movies to be witty and clever and hilarious and he brought a large chunk of the funny - and yes, the movie would have suffered were he not in it, but that was not due to a lack of anything else interesting going on. He might have carried the majority of the movie's comedy, but I really disagree with the idea that he carried the movie itself. Everybody was given equal chance to shine, which would have been an insanely difficult task to accomplish and I marvel at Joss's ability to do it.
It did serve its purpose as a 'popcorn flick' as you put it (though that term has always seemed belittling of the efforts of moviemakers who put so much time and effort into their creations) just as a comic book adaptation should. But I don't think it's
just a popcorn flick, it works on so many other levels and that's why I kept going back to see it again and again.
tl:dr, there's a reason it was so damn popular - and considering it was a movie that starred Robert Downey Jr, Chris Evans, Chris Hemsworth and Jeremy Renner and there was not
one shirtless scene among them, it certainly wasn't the lowest-common-denominator reasons that a lot of movies become popular these days.