cpanel is probably the most used control panel - they tend to be a bit cheaper than other forms. THe only cheaper one is probably Direct admin and free one is webmin, but it's not newbie friendly.
We use Direct Admin on all of our boxes except for our offsite DNS VPS'es. No problems. And it seems like the developers help out more in the support forums compared to CPanel. Feels like feedback is more important to them. Things get fixed quicker when they break as you don't have to go through a layer of folks to get a bug looked at. Just stay away from Ensim.
Different web hosting companies offers different panels and some of them can be custom made and you will be given them free of charge.
Kloxo has a history though of being unsecure. May be secure now (Don;t know. They started spamming me with the tagged email I had signed up with and it showed up on other email lists afterwards. Wasn't happy with that.) but you know there's going to be hackers looking at it closely now.
cpanel is more money but it worth the money becase it to easy to use and has many adds and worth the price
Best bang for the buck is cPanel. Its the most full features, the most user friendly and the most supported. If you are looking to spend less, Direct Admin is a great choice as others have suggested. If you want to save yourself some money, shop around at the various cPanel resellers... Some sell for a bit less than others. Prices get cheaper in volume too.
I have a question.. what if you dont have cPanel or any other panel software on your vps.. can you still do things that it does? Like setting up a default email address, adding subdomains, parked domains, etc..
Well anything that cPanel does you can do yourself if you have the proper privileges. For example, you can change the Apache config file to change the default email address. Since you have a vps you should be able to do all these but it is a bit more complicated. If you need help just let me know.
If you;re familiar with the command line for *NIX, yes you can do all that. To be honest, if you;re asking that question, I have a feeling that you;re not and some sort of panel would be best.
I would never even consider moving away from cPanel. I have used Plesk before and IMO it is horrible. Also, if you want to do full automatic cPanel backups to Amazon S3 then check out http://www.Backupalicious.com (another advantage to cPanel is that so many different things integrate with it since it is so common and so reliable)
I do have to tell you. I used to do all of my own server work. I started out with plesk. Then I moved to Cpanel. It has made me lazy and I also forgot just about everything I know. Forget about all of the linux commands I knew.