You can save a nice chunk of money if you sign up for a year or more of dedicated hosting at a time. For example, you can rent a GoDaddy dedicated server for $129 per month, but if you commit to a 12-month contract, the price drops to $79.99 per month. Chances are, if you're serious enough about your site that you think it needs a dedicated host, you're probably planning for it to be up for a year. Of course, that's where the money-back guarantees come in, and some sites definitely offer more than others in that regard, so do your research. All our web-hosting reviews cover these guarantees.
Recently, we've added more formal uptime monitoring to our review process, and the results show that most Web hosts do an excellent job of keeping sites up and running. If they don't, they suffer for it in our scoring. Even if they get everything else right, sites with uptime problems aren't eligible for high scores. All services suffer ups and downs, sometimes for reasons beyond their control. Those sites that fail to address the problem are penalized accordingly.