I've been thinking about Quicksilver's death in the movie and I think it would've worked better if it came from him trying to fight Ultron one on one, forcing Ultron to kill him with his bare hands. As opposed to the "shove someone out of the way to take a bullet" cliche which is kind of a weak and not that dramatic way for a superhero to die, to be honest.
For it to be Quicksilver, the enemy turned ally and Hawkeye's rival throughout the movie, is pretty dramatic.