Jetbeam Bk-135. It took me a long time to decide on a 1xAA light for my daytime EDC. This is the slimmest 1xAA with a clicky I could find (17mm diameter). I bought it over the newer PA-01 because it has 3 independently adjustable levels, meaning I can set up the UI any way I want, a very important feature for me.
The only place that still had them in stock was Kaidomain, and this is my first experience with them. They answered all my questions quickly and professionally and got it shipped out in one day, so I'm hoping that's a good sign.