CSS is definitely better.
1. Tables were not meant for layout
2. It's difficult to code sites with lots of nested tables and it's too easy to break the code
3. Table-less design is much easier to edit/maintain
4. With CSS you separate content from formatting. Your sites load faster because they contain less markup code. You can easily change the look and feel without altering content.
Rumour has it that CSS sites may rank better as the keyword density vs markup code will increase... This is probably true but I don't know to what extent.
IMO an important factor for ranking high in search engines is clean coding. If your code is spaghetti-like and does not make sense to a human eye then maybe it won't make sense to a robot after all :gl:
You need to put yourself in the shoes of a crawler. BTW here is a link to test how friendly your site is to spiders
http://www.spidertest.com/
A few personal seo tips that you can try:
- put your domain name in title and as close to the top as you can (I have the feeling spiders will like it because they will focus on the topmost section of your pages)
- have a meaningful <title> tag eg. myrealestatesite.com: condos for rent in Nevada or myrealestatesite.com: land for sale in Nevada
- have a consistent navigation scheme across all your pages
- use the ALT tag for images to put descriptive content about the image.
Actually I get a lof referers via images.google.com, people are looking for pictures and end up on my sites. I guess they like the images :]
- use the title tag for hyperlinks ie. <a href="search.php" title="Search for properties">