Even before I started using Linux, I had been using Firefox, Open Office, Zone Alarm, and AVG Antivirus, all of which I have been using for free. Texas A&M University has a special deal with Microsoft which allows students (like me) to purchase the latest version of MS Office for $15, so the price really isn't an issue for me. Even so, I have found Open Office to be far more stable, less annoying, and generally makes more sense than MS Office.
Two weeks ago, my roommate and I were finishing up papers for a class an hour before they were due. I was using Open Office and he was using MS Office. I had no problems, got to class on time, and turned in my paper without any problems. However, MS Word crashed on my roommates computer and his paper was lost. He tried to open up Word again to see if he could recover it (the auto-recover feature in Word is one of the few things I like about it), but then Windows XP crashed. He did not have time to mess with this, so he headed for the computer lab (which was almost completely full) to rewrite his paper. Because the computer lab was so busy, it took half an hour for his paper to print out, sorted out by the student workers, and made available for him to take to class. By the time he got to class, it was already over and the classroom was empty.
I have had similar problems with MS Office applications, but I have yet to see Open Office crash or lose a document.