A big factor is the server environment you're targeting while trying to get better desktop user support for everyday use. 
Some distros put more emphasis on server use (including being commercial options) while others concentrate on a better desktop experience, hence the following pairs:
Red Hat -&gt; Fedora or CentOS
Debian -&gt; Mint
SUSE -&gt; openSUSE

Ubuntu was a great beginner's choice back in the day, but since Canonical started to screw with things just to put their own mark on it I personally avoid it like the plague.

In the end it all comes down to personal preference if you don't have to target any existing servers.