I only just realized that this was a multiple choice poll..
Well, I would say that the edc's that I prefer, in order of preference, would be:
1. 1xCR123
2. 1xAA
3. I have also added a 1x18650 MC-E light to my edc arsenal so that will be third...
I agree with Beson... saying that any light that doesn't fit on a keychain will not be edc'd is really not accurate as I personally don't like to carry anything other keys on my keychain. I prefer to have a 1xAA or 1xCR123 light in a holster on my belt. Some people have also indicated they edc 2xCR123 / 1x18650 lights so to each, their own.
Also, I really don't like to edc 1x or 2xAAA lights in general. However, with some of the newer designs, I'm only now considering carrying a 1xAAA when I go out to more formal occasions where I need to wear a jacket and tie... sometimes even a 1xCR123 light is too much to carry around in my pocket under those circumstances... so I'm giving into practicality. But, my main edc's will always be either a 1xCR123 or 1xAA.