It depends on why you want to install Linux in the first place. If you are wanting a Linux distro that will help you build skills for professional / enterprise use, I would look to...
#1. CentOS, Scientific Linux etc... One of the RHEL recompile distributions. Far from bleeding edge, but what you will find in large / enterprise installations all over.
#2. OpenSuSe. The 2nd most popular enterprise distribution is SuSe, OpenSuSe is as close as you are going to get without a big support contract fee...
#3. Ubuntu. Being the newest kid on the enterprise block, Ubuntu is worth having skills in... They are getting a lot of traction, and are coming up with enterprise grade offerings that are starting to look very promising for the future of this distro. Combined with their work in the entire IT stack from mobile devices, and SmartTV distributions, to desktops, all the way up to servers, Ubuntu has made huge strides in usability and is making a lot of friends in IT management...
If you are just wanting to toy with bleeding edge software, then I would probably go with Fedora...