I have the heroic tier adventure modules, a few newer sets of Dungeon Tiles, the screen and D&DI. Beyond the usefulness in my campaign (I've used each book invaluably), I like to see what Wizards is doing, the new kinds of mechanics, etc. I'm a designer, and I'm always looking for inspiration.
I voted 2, although I actually got them for Christmas so I didn't technically buy them myself. I would probably have bought more, but like you I still have a 3.x campaign to finish (we just restarted last week after a hiatus, actually: The Age of Worms cometh!)Zero beyond the core book so far. We still haven't wrapped our 3E campaign.