Since I've received asks recently about Ubuntu, I thought I'd list a few reasons why I chose it for anyone looking to venture outside of sad old Windows!
It's free - to download, use, and share. Free is a wonderful world in technology where major corporations find new and innovative ways to drain money out of you just for using their operating systems. Updating or fixing problems with an OS that costs money usually costs more money. It's pretty much like paying to use a device you've already paid for. You bought a functioning PC or were gifted it, you shouldn't have to dish out more cash to use it.
Along with the general free-ness is the specific free-ness of Word/Presentation documents - it comes with programs such as LibreOffice which can read/open Word files and powerpoint files, making it easier to receive files created with Microsoft products without having to buy/update those products.
Never jump through hoops just to update software again
(Opinion) Better integration of useful applications - it's easier to manage, download, and uninstall apps whenever you want. It's also a lot easier to manage accounts and connect to things like Facebook directly from your desktop.
(Opinion) Looks great - Makes for a stylish desktop without being confined to the parameters of "We need to make this still kind of look like the previous Windows because old people are afraid of change"
Super easy to use - even if you're forgetful, Ubuntu makes it super easy to remember or learn how to use functions, applications and software. You can quickly pull up a guide or a search function any time, as well as going online to ask the ever-growing and ever-friendly Ubuntu community.
At least it's not Windows 8 - Woohoontu!