1xAA is also my favorite EDC format and I have several. Some aren't really worth mentioning, but there are a handful that I'd like to comment on.
I've got an older Zebralight SC52 (51?). It's a neat looking light and it works well, but I find the Zebralight UI bothersome and distracting in use and I've had issues with the light turning on in my pocket. A good light for jogging, but not EDC.
I have the original Quark AA Neutral. It's a bit large for a 1xAA since the head and tail were shared by the CR123A model, but the narrower body makes the it super comfortable to hold. I like the Moonlight and Low modes and am actually running it on some 14505 cells that, while they have tremendous capacity, can't provide the current for Medium or High modes. I often leave it on all night in Moonlight mode as a night light for one of the kids. If I've done my math right, I can use it as a night light every night until my youngest is in highschool before I've used up all the 14505s I was given (I don't actually know their shelf life, it's quite possible that some of them will go bad just waiting to be used...). Anyways, I love that this light can use any battery that can fit no matter the voltage and has useful low output levels and a perfect beam pattern.
The MDC AA Neutral from Malkoff is an interesting light that I've gotten a lot of use out of in the last year. It's heavy but has an awesome clip that just makes the light disappear in my pocket until I need it. The body shape is comfortable to hold and the beam is beautiful. I like that the modes are strictly ascending although I do occasionally have it start at a higher output when my previous use had been quick enough that the timer didn't reset. I do notice the PWM on lower levels, but I like the rest of the light so much that I'm willing to tolerate the PWM. I would definitely recommend this light to anyone who wants a substantial feeling light and isn't allergic to PWM.
I recently bought the Fenix e12 as a xmas gift to myself. It's the smallest AA light I've ever owned and yet it still has a clicky (I only do twisty for AAA lights). It has no PWM, no memory, and always advances through the modes in the correct order (L->M->H). My only gripe is that in order to make the light as small as possible, they use a TIR lens instead of a reflector. The beam is fine in actual use, but it looks strange when white wall hunting.
Finally I have a Defiant 1xAA that cost me $4 several years ago. It looks ugly, is made of cheap feeling plastic, has a reverse clicky even though it's a single mode light (why?), and has a big head that makes it unsuitable for pocket carry. However, the beam is beautiful and it will suck an alkaline cell down so far that it won't even show up on my battery tester. I run all my "dead" batteries through it before recycling them to get the satisfaction that I've gotten every last bit of juice.
--flatline