I've use a number over the years. Much depends on how technical you or your employees are. If you need pretty fully managed hosting, I've been with SurpassHosting for some years now (they were my backup host for many years) and have had few complaints. http://www.surpasshosting.com/
If you are more technical and want the power of a dedicated server without the cost, check out Slicehost or Linode. Linode is cheaper, but they both offer about the same product. I use Linode at the moment, but I've used Slicehost in the past. http://www.slicehost.com/ & http://www.linode.com/