In the move to digital, I'm losing my preferred aspect ratio of 6:7. With 35mm being the standard and digital following on, 3:2 is what I get out of the new camera by default. It's fine in landscape, but I'll be cropping anything portrait to 3:4.
I had a phase of 1:1 being all I'd shoot, but that was a consequence of using Holga and Bronica medium format cameras. I don't really like that for composition anymore.