Answer:
great question :) :) :)
advantages: free, upgraded frequently and each update requires MUCH less time that on windows or Mac, no viruses threats, more control to your computer,can run windows applications using "wine", if your'e a hacker its the one for ya ;)
disadvantages: you cant use windows applications (actually you can with wine), Mac has better graphics :P, if youre into gaming some games don't work on Linux and if you run them on wine then their gonna be slow