Debian and Arch are my two favorite Linux distributions. If only Debian distributed a version compiled for an i686 also. I know it probably wont make a huge difference for most programs. But it niggles at my sensibilities that I am not using the architecture to its full. Arch is pretty awesome in that field, but I would be wary of running it on production servers. For me Debian testing has been the best compromise, and I have never faced stability issues with that.
Edit: corrected by removing "and x86-64"