I've been experimenting with Linux Mint lately, and I have to say that I like it much more than Ubuntu.
Since Linux Mint is just a variant of Ubuntu (if you don't get the Debian edition, that is.), their a lot alike, but the biggest difference is the user interface, and what's included with your installation package.
When Unity came out for Ubuntu, a lot of people got upset. Not only is it (this is a direct quote from a friend) "so fucked up that I wanted to switch to Fedora" but it's glitchy too! With Linux Mint, you don't have the Unity bar. You do, though, have a Windows bar-esque start menu dubbed the "Mint Menu", which I find really, really handy.
Also, with Mint Katya you don't have to use GNOME 3 like you do in Ubuntu Natty. With Mint Katya, you have the option of using GNOME Classic, which, in my opinion is way better.
Now, with Ubuntu Natty, the included software is good, but it doesn't stand up to what Mint Katya delivers. The default installation comes with LibreOffice, Firefox, Thunderbird, XChat, Pidgin, Transmission and GIMP and other various software.
Now, what Linux Mint lacks is the amount of user support that Ubuntu has. There are many, many Ubuntu websites devoted to support, fanbases, and software. This not being the case for Linux Mint, could be problematic to some people that some how came across a unique problem that isn't covered by the Mint FAQ page or isn't well known enough to be solved through a forum.
Now, all that being said, I'm proud to say that I now have a 350gb partition of Linux Mint on my computer along side Windows 7, which I'll be using for games.
Check out Linux Mint here!