I feel sick
This review may contain spoilers. I can handle the truth.
When Scarlett Witch asked Ultron if he knew how painful the death of her brother was for her, I covered my eyes. I had the dumbest possible idea in mind of how the scene would end, and I was scared the movie would go for it.
So yeah she pulls out Ultrons robot heart and says in an offensive slavic accent "It felt like this". Bonus stars for that surreal experience.
But otherwise I'd say that Age of Ultron is a mess. This movie is best viewed in the form of Youtube clips of the Avengers quipping the hell out of each other.