I don't want to start a flame war here, because I am no fan of Microsoft, but they clearly have a huge lead over everyone else in the area of clean crisp fonts. I understand that this is a patent ownership issue. I went from Windows -> Linux -> Mac OS X over a period of several years and so I have seen a wide spectrum of font rendering. Windows beats everyone, hands down.
Font rendering tends to be downright horrible in Linux, with whole web sites dedicated to doing the best you can to crisp it up. Again patents are the issue, with Microsoft and Apple reputed to be the legal owners of the leading technologies. With lots and lots of work, and judicious selection of the fonts you use, you can make font rendering acceptable in Linux, but it never gets close to Windows.
When I first started test driving Macs, the first thing I noticed was the lower quality of the font rendering vs. Windows. It is better than Linux, but lesser than Windows. I took that into consideration as I decided on my next computer. In the long run, font rendering is "good enough" on Macs to be acceptable, but it still bothers me. A great many fonts simply aren't crisp like they are in Windows. I have been around, and I know all about the Preferences settings in this area, and TinkerTool's adjustments in this area, and yet I still can't get the clean rendering that I get in Windows.
This is not enough to make me go back to Window - as I said, fonts are "good enough" in Mac OS X, but it is something for the original poster to keep in mind. Font rendering is different here in Mac OS X. Get used to it.