It will be all 6 by the weekend - I have tickets for HBP on Saturday! My folks saw it last night and loved it. I can't wait to go.
I've seen the first 5 movies too many times to count. Last year while I was recovering from having my wisdom teeth out, I watched all 5 back-to-back.
I've read both the US and UK versions of the books. They're basically the same - the first book is called "the Philospher's Stone" instead of "the Sorcerer's Stone" and there are some little differences with the language in the earlier books, but it's fun to have both versions.
And when I was in London last year we went to Kings Cross Station - they do actually have Platform 9-3/4 spot set up with half a luggage trolley sticking out of the wall. It was really cool!