The answer to this question can quickly be determined by first establishing a purpose and settings some objectives for your website.
As an example, lets say you have a restaurant with the following goals
1. Increase Returning Customers
2. Increase New customers.
Now that we have established the purpose of your website, we can focus on objectives.
Increasing Returning Customers: What are some ways we can bring back customers through your website? First, we want to make sure the basics are covered by ensuring information returning visitors are interested in (Menu’s, Location, Hours..ect) are easily accessible. The second is we might want to offer (in a non-intrusive way) some form of incentive for the visitor to come back to your restaurant (i.e sign-up for our newsletter and get X amount off..ect).
Increasing New Customers: What are some ways you can bring in new customers through your website? Making sure your on-line presentation is solid by placing inviting pictures, descriptive and easily accessible menu’s (with pictures of food items) + call to action (exclusive first time customer coupons via none intrusive click here button’s).
In closing, what ultimately makes a good website is how well your website is meeting objectives. Since every business is different, what ultimately makes a good website will differ from website to website.