Guardians of the Galaxy
People rave about this one, and while I enjoy it, I don't think I quite understand the adoration it receives. It's a good movie and a welcome change of pace from the ones before, but it's far from top-tier Marvel imo. Still, I am mightily looking forward to these guys meeting up with everyone else later on.
Avengers: Age of Ultron
This one massively disappointed me at the time it came out, but watching it again now it was better than I remembered. It's still not a patch on the first Avengers (and the finale being a carbon-copy of the first really drags it down in the last act), but there was a lot more to like than I remembered. Another great MCU villain in the form of James Spader. Still, the final shot of the "new" Avengers assembled undeniably leaves you with a slightly deflated feeling of "Oh... So we've got those guys now..."
Ant-Man
This was the first one I skipped at the time as burnout began to set in, although I had seen it since. Watching it on it's own it felt thoroughly forgettable, but seeing it off the back of several sprawling MCU epics, it's more mundane tone actually worked in its favour (as did the more overtly comedic slant). I still think this would've made more sense as the first film of phase three rather than a slightly lacklustre conclusion to phase two, but there we go. Oh, and Michael Douglas' digital plastic surgery is still far and away the best digital de-ageing I've seen, and probably the only time the technology hasn't wound up looking entirely creepy.
So that's phase two done. Summary - I'd say this round was more consistently good than phase one. Iron Man 3 and Winter Soldier were both stellar and the one-shots finally came into their own (especially All Hail the King) - so it's slightly ironic that they then stopped doing them.* Of this phase I'd say The Dark World was the only one I struggled with.
Onwards to phase three.
*I'm aware they did some shorts for Ragnarok, but as I understand it they're jokey mockumentary-style things rather than in-universe short films.