You're going to get many varying opinions... but this is the basic jist:
What do you do with your computer?
If you're a gamer, Linux isn't the OS of choice. (Of course this depends on the games you play, as some games are Linux-ready right out of the box). Most of the most popular games will only run in Windows... even when using Windows emulation in Linux.
If you do office / productivity work on your comp, then Linux becomes a much more attractive option. It may not be totally secure, but it is definately more secure than Windows. Very few viruses exist for it. Most Linux users say that it's more stable than Windows... though I'm not having any stability problems with my Windows install.
As Linux_0 would say, Linux is very easy to fix when it's broken... in a lot of cases, Windows requires a complete reinstall... depending on how badly it's messed up. Linux just requires restoration of it's configuration files to get it back up and running.
There are many advantages to Linux, but it does take some getting used to. It's definately a more "hands-on" OS than Windows. You may find yourself having to build modules or recompile the kernel to get some things working. Once your used to this, it's not a problem... but it can be daunting to Linux noobs. (Like myself).
Once you do get it up and running, it is an amazing feeling of accomplishment. You'll never get that with a Windows install... unless you have a lot of problems with it.
