Yes, I know I'm 3 weeks late, but it ain't easy to go to the movies w/ 3 kids under 6. My wife and I saw it in 3D last night. Here's some thoughts. Feel free to discuss.
1. Shocked that they killed Agent Coulson. However, it carried a lot more weight than if they'd killed, say, Marie Hill.
2. The woman who played Marie Hill was AWFUL. Low point of the film.
3. I look forward to seeing it in 2D because many of the action CGI sequences ended up blurry.
4. Jeremy Renner was awesome. He and Black Widow need their own movie (a prequel, I think.)
5. Thanos is an interesting choice for the next villain, instead of, say the Skrull. Perhaps an invasion for a third movie?
6. How did Thor get back while the bifrost is broken? They made a big deal out of that in Thor, and ignored it in Avengers. Kinda weird.
7. Great movie. Great lines. Great action. I hope this elevates all the upcoming marvel movies.
Edit: I didn't realize the Chitauri are the Ultimate counterpart of the Skrulls. However, they didn't shape shift in the movie, so ...?