Matt Cutts from google says that it does not matter to google if you have a Css Based Website or a html table website. They have to cather to both. Most sites these days uses css because its easier to change plus its lighter because of less codes.

Tables vs. CSS does not have a direct impact on your rankings, but it helps your site to be better for your users (faster response, better layout, better accesibility, more flexibility, etc).

Matt says that if you have the best site, Google will find it and will rank it high no matter if its a table base website or a css based website.

Thats cool to know because I always have thought that css based website is ranked higher because there isnt alot of junk html lying around. I guess not!