Wow. That is a very vague question. But I'll give it a shot.
* Great wording and flow.
* Uncluttered design.
* Guarantees of service advertised.
* Support services advertised.
* Benefits that seperate you from the crowd.
* Pricing that doesn't scream overseller.
* Plans that aren't ridiculous. ie 50Gb space / 500Gb bandwidth on shared server.
You should come up with affordable feature-packed plans and always remember to deliver on promises about the aspects of the business to your customers with your reliable support and additional service they might need.