I love doing these threads (although, my wallet doesn't; you guys make me spend).
What's your favorite piece of kit, and why?
Call me crazy, but my personal favorite is the Thermarest Z-lite Sol, torso length foam pad. I had a very expensive inflated Thermarest Neo-Air for a half a year before I gave in to desire and grabbed one of these $30 wonders. This thing is beautiful for quick naps, as a support under another mattress, looks completely bombproof, and there's something about that color. I've slept comfortably on hard floor using just that; if it wasn't so cold, I'd abandon my inflatable completely! I love this thing!