I've used Linux for about 5 years now. I used to use EXT3 until EXT4 came out and matured. I now use EXT4 for all of my Linux boxes.
Which version of Linux is better is not a question that can be answered. The beautiful thing about Linux is there are so many different varieties it provides you with so many options on the table for different scenarios, something Windows and (especially) Mac fall extremely short on.
Linux Mint is based on Ubuntu. Ubuntu is based on Debian. I have used Ubuntu for about 5 years, among a dozen other Linux distros. Linux Mint is definitely a good distro, but I haven't seen anything about it that would make me want to use Mint instead of Ubuntu. If anything, I feel like Ubuntu provides more for the end user. However, both of them are very robust and I like using both distros.
Try each and see what fits YOU. That is the only correct answer to your question.
EDIT - I also recommend you register to UbuntuForums.org. Tons of friendly help there. There's also a forum for Linux Mint as well if you choose to use Mint instead. Forums are a great way to get questions answered and receive help from other users, developers, etc.
Peace - No, you are a moron. Linux is used in thousands of servers worldwide. Recently Google ditched Windows on employee computers, and only uses Linux and Mac internally. So does the US Department of Defense, the US Navy, etc. Linux can do far more than Windows can ever hope to do. It's easier to use (however this wasn't true just a few short years ago), more customizable, and best of all - more secure, stable, and free. I have used Linux exclusively for the last 5 years, and have had no major issues with it. I suggest you try it instead of bad mouthing it, since it's pretty evident you have no experience with it. This is also coming from somebody who works in an environment with 2,000 Windows systems and also dual boots Windows 7 at home. However, I've learned the only thing Windows can do that Linux can't is game, hence why I dual boot. But that may be changing this year. Keep your ears open. ;)