Hans death for sure. getting killed by his own son.

Luke's death is my favorite moment of these, and even though it's sad, I wouldn't say it's tragic at all. It follows such a monumental victory for him that his death is better viewed as his final step towards enlightenment as he passes completely into the Force.

For that matter, Ben's memory of Han isn't tragic either, since it leads to his renouncement of the dark side.