As someone that uses both Ubuntu and Windows on daily basis, I find it odd when I hear that you can't most of the things you can do with Windows on an machine running Ubuntu(or with any other GNU/Linux distribution for that matter).
While it's true that there is some software that's only available on Windows, it's hard not to come across with an analog on the GNU/Linux camp that can do the job at least as good than it's Windows counter part. For general computer users, in many cases there are actually several options to choose from to fit their needs.
For example, on Ubuntu you can use Firefox or Chrome to browse the Internet. There are several chat clients, like Pidgin and Empathy, if you are an active user of those services. Even Skype is available on Ubuntu, you can keep in contact with those of your friends and family who use it on regular basis.
If you need a robust office suite to work with, you have the option to use LibreOffice or Apache OpenOffice, among others. With them, you get all the thing you expect to come with a modern office suite.
These are just some of the examples, in many cases I've found that there are just some very specific needs that are obstacle to make the jump to an GNU/Linux distribution. The main reason I've come across, is the fact that a software needed hasn't an analog the GNU/Linux camp, or migration isn't possible because isn't practical to move the data.
After about four years of continuous use of either Ubuntu or Linux Mint, I can say I don't miss Windows at all. I found the transition to be quite easy, even thought there were some hurdles they where easy to ever come.
Most of those hurdles where just little habits, that I was able to change in a few days of constant use of the new operating system. Yet, I found that all the software I needed is available and works well. Some of the harder problems I came with, where solve fast with some visits to forums on the Internet.
It's important to note, that you don't need to have to much of a technical know-how to use Ubuntu or Linux Mint. While having it won't hurt, and helps to do some advance things, you won't be hindered on the use of Ubuntu or Linux Mint for every day shores like browsing the Internet or listening to your music.
If you want to have an operating system that gives you the freedoms that come with FOSS, and it's easy to use, I highly recommend using Ubuntu or Linux Mint. So, come on and join us on this side of the fence.