2) Windows. Everything is slammed into pixel boundaries, making it look clean. Verdana is optimized for this style of rendering, so it doesn't look terrible.. but it's definitely not accurate.
3) Ubuntu. Worst of both worlds. Fuzzy and inaccurate.
ubuntu obviously chooses sharpness over balance (H and E), however osx has virtually every lowercase character heavily aliased, its blurry to the point where its almost 2 shades lighter than its supposed to be and there are individual characters A, u, B, a where it is almost a joke
Ubuntu has similar (but not exactly the same) levels of fuzziness, but the rendering is inaccurate. Character tracking/spacing is the biggest issue, but there are others.
If you look at traditional fonts that are designed for print or general purpose use (e.g. Helvetica, Frutiger, Univers, Myriad, etc.), the accuracy and quality of OS X rendering stands out considerably. There is simply no comparison.. and once you get used to it, the small amount of "fuzziness" that you observe in small point sizes just doesn't bother you anymore.
I use osx every day, I am very used to it, I just prefer ubuntus rendering by quite a long way
I use Ubuntu configured to use Windows style hinting without sub-pixel smoothing, and I have absolutely every font forced to Verdana. I'm glad that there is accidentally a little bit of logic behind my choice.