On the same website you could look at the page presenting (what they call)
the top ten distributions.
As a Slackware user, I would of course suggest you give it a try
There are many reasons for which some people love it and others hate it and this has been discussed many times so I won't elaborate on the pros vs cons.
But this is a good playground to learn the basics of linux and the commands, because it includes very few customizations of the software shipped with it. As the old saying goes, learning Slackware is learning Linux. Furthermore there are a lot of people at LQ especially in the Slackware forum eager to help beginners.