CPanel is the most popular control panel solution on the market. Nearly all web hosts are currently using this control panel, except for those hosts that do not want to pay the expensive price tag. CPanel allows the web host to easily customize the features/programs that appear. Additionaly, CPanel has a skinning feature, that many hosts prefer, to customize the look of the panel.
If you are looking for a user-friendly control panel, look no further then CPanel. However, if you do not have much money to spend, chances are you can find a better deal on web hosting if you choose a host that has one of the cheaper control panels, like Ensim and Plesk. It should also be noted that with the extra features included in CPanel, there tends to a few more bugs than with the other two control panels.