I know Age of Ultron will win this poll by a lot, because it is Marvel, but eh, they're about even.
I will give the edge in my vote to Apocalypse, because I liked Phoenix, the Quicksilver scene, the scene where Erik loses his family, and the amazing Beethoven/nuclear scene with Apocalypse. It is the one scene where the villain lives up to his promise, but it's one more than Ultron ever got. I also think the only scene with any life in AOU is the party scene. It is great, hence why
all of the marketing was built around it.
But the rest of Ultron is pretty blah. Maybe so is Apocalypse, but I liked a few more elements in it. At least Apocalypse felt like a (bland) movie. Ultron to me felt like a sitcom. And not a very good one when it was trying to force that horrible Black Widow/Hulk love story. As well as how it awkwardly would come to a screeching halt to set up Thor 3. Then again, so did Apocalypse just to fan service Wolverine. But I like Wolverine more than Thor, so that gives it a nudge too, and at least it was fan servicing this movie and not one that two years later still has not come out.
P.S. Apocalypse hands down had a better score though. Call the movie mediocre, but that music was fire.