I was surprised to find my lowest score was from my 8800 gtx for graphics =P. I guess windows 7 really likes quad cores, and isn't fussy about memory clocks (running ddr2 @ 800mhz).
I made a HUGE blog post about Windows 7. I'm switching from vista to 7 now, because I believe it is the best Windows yet in all the important aspects, even in RC. In spite that their are tons of flaws with Windows 7, that seems to me like typical Microsoft ideas gone wrong. Here is my blog post, which makes it seem like I think Windows 7 is terrible, however I didn't mention all the things that just worked. Here's my blog post: http://thejasonride.blogspot.com/ . Please excuse the lack of real posts there... I used it for a week then stopped, and I'm using it again, just as temporary till I get my personal website back up with my own blogging system.
system: q6600, 4gb ddr2-800-4-4-4-12, 2.32 TB 7200 rpm 8mb cache, 8800gtx, and that mobo that tom's uses for core2's =P.
So ya Windows 7 > Vista > XP. However I still believe Mac OS X > Vista ~= Ubuntu. Ubuntu is better, but Vista comes with less headaches... at least until you want to configure particular parts of the OS... then Vista is more of a headache... Yay proprietary!