Only one: JH13s. If I only had one, it would have to be closed, sound great out of a source as mediocre as an iPhone, and scale high with TOTL sources and amplification. The JH13s pass those tests with flying colors. Caveat: I just received the Heir 8.As and feel like they might bump the JH13s out of this spot, but that is much too premature at this point.
2nd: SR-007 MK1. I prefer the slightly darker, laid back presentation of these over the SR-009, who's incredible detail retrieval is fatiguing to me. It's the best headphone I've ever heard, and only doesn't take first billing because it's open and is chained to large amplifiers.
And if I could cheat and keep a 3rd, I'll throw a curve and keep a Yuin PK2, a remarkable little earbud for the quick listening sessions.
Edited by Failed Engineer - 5/15/13 at 7:41pm