Tbh of all the characters who died I would probably go with Colin, but from this list and going off the events of the book, I would say Fred.

I would Wanna do Lily or James, but they’re deaths, more so Lily but still, play important parts of Harry survival on the night of the attack

Fred, because I can't imagine how George could live without him

Fred because I imagine losing your identical twin is like losing a piece of yourself and Fred and George are 100% a package deal

I'd like if all could be saved, but if I could save one, I'd say Fred, for the reasons that have been given.

Hey, moving to opinions category

I’d save Tonks and/or Lupin because they had a kid to raise.

I wouldnt vote James🎉⚡️🎈🪐 or Lily ✨💍🌸💗cuz without them dead ☠️ The books/films would have been meaningless