I'm not as obsessed with K-On as I am with some shows, but I have some stuff.
Besides the PSP game and accessories from last page, I got the two TV series BDs and concerts, and the original series comics (haven't gotten around to the newer ones).
This lighting makes the cases look red, but they're actually pink.
The second season BDs come with life-size cloth posters, and I'd been planning for ages to put all of those up, but they come wrinkled from being folded and need to be steamed. I did it for the first one (Yui) but never got around to the rest, and now I'm going to be moving soon so not going to bother at this point in my current house.
But here's a google image search link for what they look like:
K-On!! Cloth Posters
I did buy most of the music also, but in download form, so no photos of CDs to show off. (Significant demerit to digital distribution!)
At one point I got a Mugi mousepad but it wore out really fast and contributed to me swearing off buying character goods for practical-use items.
Mugi pillowcase is still in-use though.
Does this help any with contributing creepiness?
I'm afraid I don't have any body pillows
.