I am going to write up a few of the things that make Ubuntu Linux a more comfortable software development, writing, research, and having fun environment. I hope that readers of this blog add their own suggestions in comments (remember: I moderate comments to avoid publishing SPAM so it might take a short while before I see your comments and approve them).
I use Evernote and the Kindle reader a lot and there are no officially supported Linux clients. Evernote has an open source client client NixNote that is OK but I prefer to simply use the web interface on the Chrome web browser. This is a little slower than a native client with local copies of everything but it is OK. I also use the Evernote Chrome plugin. For reading books I buy for the Kindle the Chrome Kindle plugin works fine, especially since I own a Kindle device and my Samsung Galaxy 3 III phone (with 1280x720 screen resolution!!) is also good to read with. One serious problem is watching Netflix movies on Linux. I get by using our large TV with Google TV or my iTV (a gift from my stepson last year). Also watching Netflix and Hulu+ on my Samsung Galaxy 3 III is fine if no one else is watching. I also have an iPad 2 I bought last year that works well for watching video; I am planning to swap this out for a Nexus tablet that has a smaller screen but higher resolution than my iPad 2.
Other tools I use everyday work fine on Ubuntu Linux (sometimes with some adjustments): IntelliJ, RubyMine, LaTex tools, Emacs, git, etc.
For many years I wrote copious work notes in a physical square deal style laboratory notebook. I switched 20 years ago to using plain text files for copious work notes on everything that I do. Now I organize notes differently using a combination of Google Docs (back them up often!) and RTF formatted text files that are a little better for me than plain text because it makes it easier to tag different kinds of content with styled text and different colors - this helps me find things faster. I like to use AbiWord to quickly open, edit, and view RTF files - faster and lighter weight than Open Office or Libre Office.
For a lot of what I do there is little difference between using Linux, OS X, or Windows. Interacting with customers using github and Google shared documents is the same. To be clear, which desktop (or laptop :-) operating system people use is their own choice. For me, being able to apt-get install software and have the same environment on my laptops as on my servers make using Linux a great advantage. For most casual computer users obviously Windows or OS X is a better choice for them.