I think that Harry should die. If not, then I think he should live but lose his scar and not marry Ginny. He should go crazy and teach Defense against the dark arts, and constantly yell at his students that he defeated Voldemort, and they cant even do a simple charm.
I think that harry should have died and that Voldemort should have taken over the world. What's so bad about what Voldemort is doing anyway? He's only wanting to get rid of Muggles? Who cares?
Honestly, I liked the ending the way it was. It wasn't too depressing like Mockingjay from the HG, it wasn't too happy because Tonks, Lupin, and Fred died. =( And it was realistic in the sense that you knew it was war, but when they had victory, you felt triumphant. I loved the ending.
Just my opinion. ;)