Ubuntu 10.04 is an LTS (long term support) release, which means that there will be security updates made available for a longer period of time than you would get with a non-LTS version.
You can read more about how Ubuntu handles release cycles here.
Ubuntu is a very flexible operating system and is perfect for anyone who wants to run a variety of services on a LAMP system.
For example, you could run:
- email servers
- database servers
- development servers
If you want to play around with a variety of open source technologies a recent release, such as Lucid Lynx is ideal.
UPDATE: Just for a laugh I got an output of the exact version information from a VPS running Ubuntu so you can see it:
Distributor ID: Ubuntu
Description: Ubuntu 10.04.1 LTS
NB: You CANNOT run Plesk on an Ubuntu VPS.