I literally devoured this book. I read it so fast and loved it so much. I bawled my eyes out at the end and gripped the book so hard in frustration through the rest. I know the truth about Snape as I've seen the movies, but reading about his wish-washy ways still angered me. The explanation of the Horcruxes was very helpful, as I don't recall much explanation of them in the movie, or I just wasn't paying attention and found myself confused over them in the movies. And Hagrid caring for Aragog was sweet and yet disturbing (big spider hater here).
I loved the Pensieve parts where they went and watched Tom Riddle's life, it was like learning about someone you actually knew, where after you look at them in a different way. You wanted to have sympathy for Voldemort, yet you know that it's completely wrong to do so.
And ugh. The death of Dumbledore was hard! I knew it was coming having seen the movie prior, but it didn't mean I was any more prepared for it when it came. The way it was written was both sad and beautiful. And I enjoyed reading about it more than I did watching it.
All in all this was a really good book, and I'm already delving into Deathly Hallows with a review soon to come.