If industry-leading uptime and rapid-scalability are your two biggest concerns, cloud hosting might be just what you're looking for. Cloud hosting will get you access to a cluster of servers from which you can quickly provision resources when you need them. Along with having enough separation from unruly neighbors, your application should be kept safe. VPS and Cloud services are sometimes combined into a hybrid service called Cloud VPS or Scalable VPS.
Established back in 1998, LunarPages operates three state-of-the-art data centers. Equipped with multiple GigE fiber connections to the internet backbone, the company built out seismically-braced racks and cabinets, fully-redundant Liebert HVAC cooling systems, a diesel generator that can run for weeks, and a pre-action dry pipe fire suppression system.
Dedicated hosting is not for everyone and generally provides more resources than the average business requires. Dedicated hosting is ideal for very large companies that regularly experience a high volume of internet traffic or sales, or require a large amount of disk space. Dedicated hosting grants you the greatest flexibility, customization, and security of the three types of hosting but is also the most expensive.
Many services offer a low "starting price," but require you to prepay for two or three years of service to get that price. After the promotional period, the renewal price for some services can be two, three, or even four times the initial promotional pricing. While the initial deal might be incredible, the cost of transferring your site (or paying the added fee) in a couple of years may be something to consider.