In my search for a web hosting company that caters for resellers like myself I have tried a number of them.
Now my reseller hosting requirements are particular in that I don't offer hosting for websites that I have not been directly involved in. However I do need a cPanel account for each website so that the end user can manage their own site.
I also need good technical back-up and the option to have some additional server scripts loaded, for example Drupal likes to have PECL Uploadprogress Library or APC.
Most host will not move from their default install but one ticket to Scala Hosting and they had it done within two minutes.
They also have great ratings at Web Hosting Stuff, which I recommend you to look at.
Just to be clear I am not part of or employed by Scala Hosting although I do get a little bit through their affiliates program.
So please go check them out - great for Drupal, Joomla and WordPress sites.