The most critical part of your website is content.
How search engines rank your site is highly dependent on your choice of keywords, how the keywords relate to your services, as well as the opportunity for creating reciprocal links among other websites.
BK's site is a great example of this. When people start to use your site as a reference for content it not only drives additional traffic from the referral, but places you in a higher ranking within the search engines.
While you'll want to have a great looking site it's really secondary to this. People won't be coming back multiple times because your site looks cool.
