I absolutely loved reading about the Quidditch World Cup (well, the actual match, I feel too sorry for Winky following that haha). It was fascinating to see how Rowling created a whole new sport and I wish we could actually play it. Off the ground etc. Haha. I loved the conjuring up of patriarchy from both Ireland and Bulgaria and thought that the use of the Leprechauns and Veela was so cool.
I loved all the planning that went into it. The portkeys and the ensuring that Muggles can't see or get involved with anything. It was something so different in the series. It was nice to see Harry as a teenager free from worries for once in the series. It isn't often that he gets to embrace the more normal aspects and it was really great to finally see him let go for a little while.