There was an example that I used to use to illustrate why I prefer using a Mac.
DISCLOSURE: I use and provide support for PC's in my line of work, and I use them and they work very well in a lot of situations, particularly a corporate environment that is very structured and protected from viruses. I use PC's, but I enjoy working with Macs!
On my Windows box, I would put a floppy in the drive and begin copying something to it. Floppies are pretty slow, and sometimes, it would take a while. You would watch the indicator, and it would get to 98% and say something like "There is not enough room to copy the files to disk". It would try to copy and get all the way to the end before letting you know there wasn't enough room on the floppy!!!!!!!
On the Mac, you could bring up a save dialog box, and if you inserted the floppy at that point, it would automatically switch you to the directory on the floppy because it assumed you wanted to copy to it because you just inserted it...plus...it would check the available space BEFORE it tried to perform the copy operation.
Small thing, but I always used it as an example of the attention to detail that makes them fun to use.