1. Windows
1.1. Pros
1.1.1. boots quickly, about 8-12 seconds.
1.2. Cons
1.2.1. gaudy colors, boxy designs, applications that can either run as a small tile or as full screen with no way to resize or move windows
1.3. Pros
1.3.1. most desktop and laptop computers use Microsoft Windows
1.4. Cons
1.4.1. Too old, too slow
2. Mac OS X
2.1. Pros
2.1.1. OS X does not require you to put in code in a terminal to get some applications and to get them working
2.2. Cons
2.2.1. OS X requires luck or some knowledge to use all the basic features
2.3. Pros
2.3.1. OS X does not require you to put in code in a terminal to get some applications and to get them working
2.4. Cons
2.4.1. OS X requires you to buy these basic applications to do every day task
3. Ubuntu
3.1. Pros
3.1.1. Virtual Desktops are insanely cool
3.2. Cons
3.2.1. sluggish from time to time
3.3. Pros
3.3.1. Beautiful Themes
3.4. Cons
3.4.1. Ubuntu is about 2 GB