We have been using Ubuntu since the older versions, but canonical has changed their OS to a newer level by releasing the new version 10.04. I think this is the best Ubuntu I have ever had and there are basically two major reasons behind this thought.
Comprehensive software updates
Worlds most deadliest security vulnerabilities are coming from third party applications, Windows and Mac machines are at significant risk because they run lots of these apps and those apps are not always updated automatically, which leaves the machines open to attacks.
With Ubuntu, it has a comprehensive update system. This is possible because of its centralized software repository and the applications that make to this repository are tested by Canonical (the company that produces Ubuntu) for its stability with Ubuntu.
This means that the Ubuntu main repository does not always have the very latest version of Firefox, for example, but you can be sure that the one it does have will typically install easy, work smoothly, and remain updated automatically.
Integrated app store
While Ubuntu's software repository is managed by an application called Synaptic Package Manager, there's also a much easier way to browse through the official Ubuntu-anctioned applications, its called Ubuntu software center and its simply like the Apple App Store. This applications library will help you to install those stable applications those are tested and verified by Canonical for Ubuntu use. Software installation through this area is like you do in Windows only, select the application you want to install and start the installation.