All in all, one of the best films I've seen in a while.

Rating: 10/10 (28 April 2012)

Cannot find too much fault in this film, apart from maybe the fact you will need to have seen all previously related films, luckily I had seen Iron Man 1 and 2, Captain America and Thor, so I knew the back story from the get-go.
I feel all of the characters were given enough screen time, I would have maybe liked to see Thor a bit more, I think he was underused, he could have done a lot more with his massive power, like killing one of those massive lizard things on his own, the character of the Hulk was brilliantly well played by Mark Ruffalo, he portrayed Banner as a very calm and collected man and very laid back which is needed for him, it created a newfound interest in the character for me, as I was never a great fan of the Hulk. As always Robert Downey Jr did a fantastic job of Iron Man, with the majority of the film's funny lines coming from him.
Chris Hemsworth borough back the mighty Thor and did so tremendously, like I said I think he could have been used a lot more, the Black Widow was also a nice addition, even though she had appeared previously in Iron Man 2, (although the tight leather outfit was a bit distracting lol.) I found it incredibly hard to stop looking at her behind, but luckily I was wearing 3D glasses in the dark so nobody could tell.
Hawkeye was really well played, for some reason the actor looks a LOT like Gerard Butler to me, I don't know why. But regardless he is a great character and I found it very funny when he asked Iron Man for a lift up to a roof of a building, and Tony Stark replied "Ok hang on then Legolas". Little funny lines like that made the entire cinema laugh a lot.
The humour of the film mainly came from Iron Man/Tony Stark, also quite a lot of funny moments came from Bruce Banner/The Hulk. I was a bit confused as to why he can suddenly control the Hulk, when he completely lost control on the ship earlier on. There were deep and meaningful thoughts about Bruce's alter ego, but there was a lot of humour to be had from the Hulk as well, (particularly when he smashes Loki on the ground again and again).
One small annoyance I had was the continuity on the level of strength and toughness each character had. In the film Thor, he was made to look like the most powerful being ever, with one whack sending big ice men flying 50 feet in the air, but in this film he only whacks them back about ten feet, which is exactly the same distance Captain America and Iron Man can hit (which it shows in the fight scene involving the three of them). It's just an annoyance of mine but I found it hard to figure out which one of them had the most strength, fair enough Steve Rogers is a super soldier but Thor is a demigod, you would think he would have a lot more more strength in comparison, one second a whack from Thor's Hammer can knock the Hulk ten feet away, but it doesn't even leave a scratch on Captain America's shield? And yes I know the shield is made with some indestructible material mentioned in the Cap film, but the Hulk is quite tough too and he got knocked away completely.
I also kinda wished they fought directly next to each other more, you never see all of them at the exact same place, they're always scattered about and you never get the feeling they are a full team, throughout the film I was waiting for some epic bit where all 5 of them pulled off some unique combo that involved all of them, but the most I got was two or three of them in the same place in the final battle.
But all in all, the film is brilliantly well done, action scenes are engrossing and genuinely frightful, you get some empathy for Bruce Banner, you genuinely worry about certain characters and I for one was thrilled with it, I was worrying it might be too many characters for one film but they nailed it.