Alas, it's Harry Potter spoilers. Don't read this post since I just read Half Blood Prince and am bursting to spoil it. I thought Harry's obsession with Malfoy, even though it annoyed me at times, was more interesting than his obsession with Snape, because his judgment seems even more intensely impaired with Malfoy- spending every spare moment trying to track his movements, jumping to conclusions(just because you might occasionally have the right conclusion doesn't excuse it) and just generally being distracted. I hope he's learned his lesson after seeing Malfoy cry like a punk and after actually injuring him, but Harry's hot headedness doesn't bode well for the 7th novel, which I hope we have a shorter wait for. I had forgotten near everything that had happened in the 5th book, as I tend not to reread them.
I especially enjoyed the amount of teenage drama Rowling put into the book. I would think it was unnatural if a bunch of 16 year olds got along without fights about who is going out with who,etc. Ron and Herminone fans should rejoice as some big hints are thrown out this time. Although Rowling tends to be good with details, some just seemed to be thrown on- such as Snape being the half blood prince, and what's the deal with Zabrini? He shows up at the beginning and then doesn't have much of a role. I know this is all set up for the seventh, but as it is, it seems a bit thrown in,