Most important components of a Good website
*Unique and up to date Content is always good
*Pleasant color scheme and Graphics that make a site visually appealing.
*Consistent layout that segments the content well and visitors get what they want easily.
*Simple and easy access Navigation. Visitors should be able to effortlessly move around a website,
*Short and Memorable URL (you can also use mod rewrite)
*Faster page loads
*Compatibility with all popular browsers
*A reason for the visitors to come back
And the list could go on forever. Overall I think the site should have marketability and motivational factors for your visitors as to make them feel confortable while browsing as well as know your product or service well.
A clean layout, good design, unique and updated content all are important – but what’s the use of all these if nobody’s coming on your website and reading it. So apart from all the above mentioned points, a site needs strong marketing strategy to achieve success.