The most tragic for me was Fred's death, just the thought of all the pain George had and has to go through to keep on living himself after losing his twin, is enough to make my blood run cold. Then there is the rest of the family's pain.
Most of the deaths were just unneeded, Lupin and Tonks just after they got together AND had a child. Fred, just why? I was reading for Ron and the Twins ever since the second book.
Snape, o.k maybe his was part of the bigger plot, but did he have to have such a sad death.
Dumbledore was going to die soon anyway so I can begrudgingly accept his. Sirius was just a pathetic death, and I don't see why Luscious couldn't have been killed off, or any other random deatheater in that scene just to even the deaths out.
And isn't it a little odd that Harry was more upset about Doddy's death than Hedwigs, he'd known Hedwig longer and she was always of use to him so he should have mourned her at least equally to Dobby.
There was also Cedric Diggory's death, I really don't see why he had to die. He wasn't an important enough character to have caused big ripples to the plot like Lupin or Sirius.
I don't care much for the Potters and James did seem like a right jerk.