Tough choice. It's between Dumbledore and Hedwig. Dumbledore's death came first, and he was my second favorite character, killed by my favorite character. So many emotions. But when Hedwig died, somehow I knew that she was just the beginning, and I just saw a lot more death headed our way. So maybe Hedwig.
Remus, probably. I understand why everybody else died, but the fact that he was the last of the Marauders, as well as the fact that his death made Teddy an orphan just pissed me off. I get that there was supposed to be a parallel between Harry and Teddy, just with Teddy being raised in a loving environment, but still... *sigh*