1. The Avengers - chemistry between the characters, especially Hulk and Iron Man, was brilliant. Joss Whedon was the perfect choice to direct this, and I cannot wait to see what he does with the additions of Scarlet Witch, Quicksilver, Vision, and (maybe) Falcon and War Machine to the team in Avengers: Age of Ultron.
2. Captain America: The Winter Soldier - a very different film to its predecessor, and all the better for it (not that The First Avenger was a bad film). Captain America and Black Widow worked as a partnership, as well as Cap and Falcon, and the Winter Soldier, whilst underused in my opinion, was more menacing than any Marvel villain up to this point. Seeing Captain America in a film this good has elevated the character in my eyes, and depending on how Captain America 3 turns out, his films could be my favourites (as a trilogy) out of all the Phase films.
3. Iron Man - the one that started it all. Robert Downey Jr. is brilliant, and his change in character is pretty believable considering the circumstances he's put through. Add to the fact that he plays the billionaire playboy philanthropist convincingly and retains likeability is a feat unto itself. Would be my number 2, but I have over-watched it over the last 5 years.
4. Captain America: The First Avenger - the funniest of the Phase 1 films, and pretty emotional in its climax. The supporting cast of Tommy Lee Jones, Hugo Weaving, Toby Jones and Hayley Atwell helped make this a lot better than it should have been, considering that it, like Thor 2 months before it, were only meant to be introductions for the characters before they joined the Avengers.
5. Iron Man 3 - yes, a LOT of people were annoyed that the Mandarin wasn't actually the villain of the piece, but Ben Kingsley was so great that it was forgiveable...and it also added a lot more to the plot. The twist was a great moment, as was the introduction to Trevor Slattery who I hope we see in Marvel films to come (despite the ending of his One Shot...though that could mean anything).
6. Thor: The Dark World - Malekith should have been focused on a lot more than he was. The introduction to the film makes him out to be fearsome, but he's a pretty weak villain with not much to do after that (whether he was like that in the comics too I don't know). More Loki isn't necessarily a bad thing, but he took the limelight off the main villain when more needed to be explained about him and his race apart from 'They fought the Asgardians once and their toys got taken away'. Great fight scenes, Sif and the Warriors Three played a bigger role (which was much appreciated), and Idris Elba got to be a badass. My least favourite of the Phase 2 films thus far due to the villain, but that doesn't mean I didn't enjoy it.
7. Iron Man 2 - granted, it wasn't the best of the Marvel films, and didn't really do much apart from develop on the end credits teaser of the first Iron Man, but it was still fun. Like the first Iron Man, though, the final encounter with the main villain was underwhelming and over too quickly. Actually, scrap that, it was over way quicker than Iron man vs Iron Monger...which is odd, considering Ivan Vanko was hit by a car several times and brushed it off quickly. Would have thought a suit of armour would have made him more susceptible to death.
8. The Incredible Hulk - I liked Edward Norton as Bruce Banner...but not as much as Mark Ruffalo. Hulk smashing stuff was fun to watch, and all the hints to the wider universe (Stark Industries, Nick Fury, Super Soldier Serum) was the beginning of something. However, after watching The Avengers, this film was a bit pointless, much like Iron Man 2. Still good (none of the films on this list dip below a 6/10 in my eyes), but didn't do much for the rest of the MCU.
9. Thor - the film that made females start caring about the Marvel films because of...abs. No, seriously, my sister only saw this for Chris Hemsworth, and my girlfriend loves the Thor films because of him (two examples, but it's enough for me to reach a rather flaky point). The story itself was basic 'fish out of water' fare, with the exchange between Thor and the pet shop owner being a personal highlight. The film suffered from its purpose being an introduction to the character, but we got introduced to key players on both sides of the Avengers, as well as a MacGuffin in the end credits that turned out to be pretty important (it's always the Thor films that have the important end-credits scenes, but that's probably due to its links to the rest of the universe). Dark World improved on this film by focusing more on Thor's powers, which this film lacked, as well as making Kat Dennings less annoying. The more I think about it, this film was like the first draft of an essay - it was good, but there were kinks that needed to be ironed out.