Check out this link, I love this site: Linux Distribution Chooser
I’ve always had issues trying to decide which Linux distro (distribution) to use, only when I first was curious about Linux though. The above link is a great way to guide you to a Linux distro that you might prefer over another.
I personally have tried several flavors and remain a Red Hat based user. Obviously for home use I am using Cent OS and Fedora Core (mostly Cent OS). I have played with Debian systems, Ubuntu mostly as it sure has gained a lot of hype and now has a large user base.
If your not used to Linux I recommend trying Ubuntu, Red Hat based systems are a little more complex then the Debian based Ubuntu. There are a lot more packages and additions which are easier to install on an Ubuntu system.