Who are the leaders in true managed hosting? Rackspace gets mentioned a lot. Who else? IBM? Who should be on a short list for an critical application with reasonable budget needs?

Rackspace is probably the industry leader, but there are a number of smaller companies that will also do a great job for you. Your provider of choice would really depend on your management needs and number of servers. IBM probably won't even talk to you unless you're going to bill more than a million dollars annually.

Rackspace certainly has a name for managed hosting. Their motto is "fanatical support", and I can vouch that they are serious about providing the best support in the industry. However, like the previous poster indicated, there are a number of factors in determining your hosting provider, first of which is your technical requirements and budget. If you want a low-end shared account, then you're going to have to sacrifice on your support requirements.

NACmwinship please name some of these smaller companies, thanks

NACmwinship please name some of these smaller companies, thanks
www.HTTPme.com is one of them.

Here's a direct link to their managed servers FAQ (http://httpme.com/forumdisplay.php?s=&forumid=187). Specifically, read the thread about "What is Fully Managed?" and you'll get an idea of what they offer.

Highly recommended.

rackspace is tooo expensive and i hate how they dont make their prices available.

Thanks mrzippy!