Star Wars. It changed the way we look at movies.
I applaud JK Rowling for writing books that made kids want to read, but some fans need to take those reading skills and use them on other books and stop comparing everything to Harry Potter (Some SW fans do this too).
The Star Wars movies on the whole are better than the Harry Potter ones, even with the who’s who of British actors in them. As long as Emma Watson (I irrationally hate her) is never in a Star Wars we will be good.
On the merch front: lightsabers beat wands every time.