Suse Linux is pretty good. The only reason I am not using it is that I have not convinced my wife to leave M Office.
Interestingly, my daughter's school is running a laptop program, and it is almost entirely mac laptops. I admit pure inexperience here, just starting to play with it, but it is interesting that the operation is more or less similar to windows (ok the click location is on the left instead of the right, etc), but real close.
Also, there is anti virus s/w for Mac, along with the other normal protection programs. Not sure if that is just marketing, or needed, but it is interesting.