Alright, this review is going to have a few minor spoilers so before I get into it I'll give a quick spoiler free review. The story is well thought out, plot progresses smoothly, characters are well developed, fight scenes are awesome, and the special effects are AMAZING! The only minor problem I see with this movie is if you haven't seen all the tie-in movies, you might be lost at the start and might not connect with some of the characters at first, but I don't see this being a major problem because the characters are steadily built up and relatable. All in all I would give Marvel's: The Avengers are solid 9/10.
This is the first time that a film like this has been made. This film was literally 5 movies in the making, and I had no idea how they would converge all of these seemingly different plots. Marvel's: The Avengers manages to gel all the tie-in movies that preceded it into a well oiled machine. Elements introduced in previous movies are are explained further in this movie and are used as important plot devices, such as the Tesseract from Captain America: The First Avenger. I really like the fact that they give every character a purpose, a reason for being there, instead of just crowbarring them in. At no point of this movie did I think to myself "well this is dragging on" or "can we please get on with this story," because in each third of Marvel's: The Avengers Whedon kept the pacing just right; the first third of Marvel's: The Avengers revolved around Loki and his motivations, as well as recruiting the Avengers, the second third of the film was mainly building up our main characters, their conflicts and motivations, and the final third was all action. Pacing and tempo done right. This movie also didn't take itself too seriously, with a lot of Whedon's trademark cheeky humor well on display. Infusing lighthearted humor into heavy scenes is something that I really enjoy in a film, and there was plenty of that in Marvel's: The Avengers, as well as some major laughs!
Marvel's: The Avengers also did the action correctly. Some movies, like the Transformers movies, have a lot of action, but it's extremely difficult to make out exactly what's happening with all of the heavy cutting. Not only was the action in this movie visually stimulating and well thought out, it was extremely clear and easy to make out what was happening and who was winning in each exchange. We also got to see some fight scenes in which different characters teamed up and combined their powers to do some really cool moves, like Ironman ricocheting his laser beams off of Captain America's shield to blast a group of villains.
The cinematography was astounding in Marvel's: The Avengers, and this was most clearly seen in the fight scenes. I watched this in 3D, which is notorious for making movies look like they couldn't afford lighting, but this was definitely not a problem in Marvel's: The Avengers. The fight scenes were also accentuated with the brilliant special effects that were on display. From the Hulk smashing everything in sight, to an alien rock whale-turtle destroying Manhattan, everything looked splendid. The only complaint in this department is with the Avenger's hovering base, which looked cartoonishly fake at times, but that is a really minor complaint.
What more can I say, I absolutely adore this movie, it's worth watching opening night at midnight, and is totally a full price movie. I give it a 9/10.