I use the Google Webfonts service on my website and rely heavily on it. It renders fine on most browsers, but in Chrome on Windows it renders especially bad. Very choppy and
I develop in Firefox. My experience is that FF displays ttf fonts very well without any extra rules (beyond the @font-face calling the url for the font file). Chrome, however, is a different story. Even with with the -webkit-font-smoothing: antialiased; rule it still displays any font quite raggedly. Safari doesn't seem to have that problem, so it's not inherently Webkit that can't render a font cleanly, it's a Chrome problem.
I haven't tried adding the -webkit-text-stroke: 0.5px; rule, but will.
Of the answers above I really like Tom Sarduy's answer best. Aside from a good description of the problem, he gives a great @font-face stack to use to cover all the major browsers.