Half Blood Prince (movie), like the book, was just not all that interesting. I can see how humor was added to try and fix that, although in my opinion it subtracted from the grim mood that is needed to set up the seventh book (which is the only real point of this chapter in the HP story anyways). It was definitely not my favorite Harry Potter, and I think it could have been done better, but it is still Harry Potter (aka you must see it).
Now only 2 more years of waiting in agony for the next (and best?) one.