(Only read the first and sixth pages... no new jokes to add, I'm affraid)
In my mind, and based more on reputation than experience, the Leica's are outstandingly the best, the Minoltas, then it becomes a splitting-hairs tussle for next, being between certain Pentaxs, Nikons, Sigmas, and Tamrons, but following the pack is Canon. But Canon does have excellent marketing!
I've seen a comparison somewhere, between a Hassleblad and a new Sony A900, and it really, really was quite close. I think it was something like an 85mm on the 'blad, and probably a Carl Zeiss on the A900. For what it's worth, the bokeh on the Minolta G's make them worth the money over the CZs, from what I have seen and been able to compare.
In anycase, if I were to change teams, it'd probably be to the Nikon team.