Just in case anyone has not yet seen these, here are the three covers for Harry Potter and the Half-Blood Prince:
The US edition:
The UK children's edition:
The UK adult edition:
I like them all, but I think my favorite is the UK adult copy. It has a POTIONS book, and POTIONS mean SNAPE, and I'm ALL ABOUT THE SNAPE!!
I also think that Marie GrandPre keeps improving with each new US cover.
Thoughts, opinions, questions? :-)