and if it does rank you better in search engines, by how much? my site's aren't compliant and when I try and make them so, the whole design get's screwed. so hopefully it doesn't matter. what has every one else heard?
I don't think it matters all that much, but it does show professionalism I think. If a designer can make it W3C compliant, it shows that the person knows how to code properly and it shows the use of standards. I doubt it has much SEO effect though.
fsmedia is correct - compliant code has little or no effect on SEO, BUT... you should absolutely have it anyway! Your site should be accessible and usable as well as well ranking... it's one of the basics of web design.
Well I'd like to make it compliant but my site turns upside down when I do (tables, images, divs disproportioned).
In that case, throw your current code out and start again. Mark up the document content using semantic HTML and then style the resultant document structure using CSS. Don't think about layout while marking up the document. This also means don't use tables (except for genuine tabular data, of course), or superficial <div> tags.
There are a number of main issues behind having good valid code. 1) If shows that the designer has taken the time and effort to make the page or site compliant and shows a degree of professionalism. 2) Compliant code means that the site will display correctly across browsers - more browser based issues will arise with none compliant code. 3) Pages will load faster with compliant code as it is more streamlined and hence can (in a small way) reduce the bandwidth requirements of the site or specific page. 4) Compliant code is also good for people with disabilities who view the site (for page reading software and the like). So in conclusion - yes its very good to have compliant code