I would the closest I've come has been with Linux. I run Debian on my Powermac G3 every so often, and I did run SuSE 10.2 on the PowerBook G3 once.

I was relatively pleased with Debian on the G3 as a server, but SuSE was not that great, the interface was too big and everything took too long compared to Mac OS X, which has been doing well.

I did like YDL, and long ago I did run like, Mandrake 8.2 on my b/w, which was fun, but in general, I suppose I prefer Mac OS on Mac hardware.
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