Harry's Death
A number of people have said they thought that Harry should have died. They seem to forget the title of the very first chapter of the very first book: "The boy who lived". Why should he have died? I see no reason for him to, and have yet to see a compelling argument for his death. He was willing to die and sacrifice himself if it would put a stop to Voldemort's evil. He made his noble sacrificed, survived due to the power of love, and lived happily ever after. A much better ending then him dying and Voldemort living.
The Epilogue
Oh how they hate the epilogue. "Too Disney", or "too brief", or "they grow up to be just the same". First off, I'm not even sure what being "too Disney" means. Some people need to look at some of those movies again, and remember who dark they were in parts. I think they mean it was too happy. So what? Would you really want to read an epilogue where they didn't live happy lives?
It was brief, but this series contained an enormous number of side characters. There is no way to have covered anything more than a fraction of them. And it allows you to imagine your own endings for your favorite (or least favorite) characters. I guarantee you that the younger readers of the book have no problem doing that.
There is some merit to the argument that they grow up to raise their children the same way they were. But I read more into it. Yes Harry wants his son in Gryffindor, but he will support him if he is in Slytherin. Yes there will be rivalries with Draco's son, but there are always rivalries in school, and I firmly believe that Draco's son will be no Death Eater.
Yes Ron and Hermione still fight with each other, traits that the kids will learn, but they also still love each other and are still married after nineteen years. That makes more of an impression on their children, and ours when they read the epilogue.