I only shoot square. It's bad enough that the few times I take iphone pictures, they have to be square as well. When I had a digital point and shoot I occasionally shot panoramic, but otherwise the rectangle just doesn't do it for me.
My Hasselblad has ruined me. I've fallen in love with the square so much and enjoy the WLF and manual controls (I rather like that the aperture and shutter controls are up front there on the lens) that I'm not sure I can ever go digital. I've tried a few (with a toddler a DSLR would come in handy). But I just can't seem to enjoy the prism finder, LCD screen, autofocus, autoexposure, etc... I know they make great photos. It's just the experience that is lacking.
Personally, I find giving myself limitations (only shooting square, which I just interpret as "full frame," and using an 80mm lens for >95% of my shots) gives me more room for creativity. Initially those were artificial limitations--after buying a Hasselblad I couldn't afford any other lenses/cameras, but now I find it's a more enjoyable way to shoot. For me.