Ron Weasely can name the top five worst moments of his life without pausing for breath.
Number One is easily hearing Hermione's screams in Malfoy Manor. Nothing, no sound, no sight, no feeling that Ron has had in eighteen years of living can even come close to comparing to how desperate and afraid and angry and sad and helpless he felt at that moment. He doesn't want to admit how often he prays that nothing ever comes close. He doesn't think he can go through something like that again without breaking.
Number Two is Fred's death. Maybe this should be number one. Maybe the fact that it's not shows what a terrible brother Ron really is. If it wasn't for the Manor, this would be number one in a heartbeat. After all, he was there. He saw his brother's last moments. That moment of Fred laughing and the walls collapsing around them will always be with him. But in some strange way, the fact that he was there, also comforts him. He doesn't have to imagine what happened, what Fred's final moment was like, he knows. And he knows Fred. And he knows that's how Fred would have wanted it-he would have wanted to go out with a bang-to die laughing. Harry says that there is something after death-something warm an pleasant waiting. Because Ron trusts Harry he knows that Fred is somewhere where there is no pain or loss or sadness. With all the suffering around Ron now, he can't help but wonder sometimes if Fred is better off.
Number Three is thinking that Harry was dead. Words cannot describe the fear that washed over him when he saw Harry's lifeless body. Ron had never realized how much he had admired Harry, how much he had relied on Harry to get them all through this until that moment. Hearing Hermione's shriek, seeing the dead look in his baby sister's eyes-Ron had never felt more inadequate and unable to protect those he loved then in that moment, never mind that he believed that he had just lost his best friend, the first person that saw him as Ron Weasely and not just a Weasely, his idol, his hero, his friend. Ron actually prayed out loud for Harry to get up because he knew that no one could take his best mate's place.
Number Four is seeing Harry and Hermione kiss. With all that has happened. With all the people that have died, with all that has been demolished. With all that has been destroyed, compounded with the fact that the kiss wasn't even real, Ron knows that it should bother him less. But it doesn't. Even though he knows that what he was never was and will never be a reality, the image still eats away at him. Its burned on the inside of his eyelids, reminding him that no matter who he becomes he will always be the jealous best mate that will never be good enough for her.
Number Five isn't visiting Lavender Brown in St. Mungo's for the first time. It isn't catching his Mum crying in the kitchen when she thought no one was awake. It isn't watching Bill talk George out of killing himself for the second time, or watching George try and drink himself to death when outright suicide didn't work. It's not Dumbledore's death, or tripping over Lupin's body, or realizing he could see threstrals, or Bill getting attacked, or George losing an ear, or seeing Neville's parents for the first time, or when Mad Eye was killed. No. Those are all contenders, and maybe they make top ten, but no.
Number Five is Eloise Midgen's funeral. Why? Because Ron never knew that Eloise had six siblings, just like him. He never knew that her family was poor and struggling, just like his. He didn't know that Eloise had saved Ginny from the Carrows multiple times that year. He didn't know that Eloise's acne really had gotten much better. He didn't know that she was brave and smart-so brave and smart that during the final battle she had nursed the wounded on the battle field and set up triages that saved dozens of lives. Ron didn't know any of that-and he never bothered to find out. He had teased her mercilessly about her acne, her weight, her clothes, her braces, her hair. He had turned down asking her to the Yule Ball because he had thought he was better then her! She was so obviously better then him! Number Five is Eloise Midegen's funeral because there Ron realized that he had been a fundamentally a vain and selfish person in school and had hurt a lot of people. And that he couldn't take it back.