You may have heard "paid stuff is better than Free"(actually i also haven't heard that, actually it's is not even a quotation).
Anyways, Mr. Gates and Mr. Jobs is getting their bag to be filled with dollars which they get by selling Operating systems, then mostly in XP and also in Vista we get suffered by problem(a virus, sudden crash, or more Unknown things). An alternative of them is to use Linux, not few days ago Linux was considered a OS for only programmers and Computer experts, but now there has been a significant and noticeable development in Linux, a good linux, Ubuntu is now in the first place in all linux distributions, in which all open source softwares, which are remartkeble in their field, are used. You can get to some other Linux distros and some Open source stuff at the bottom of this page.
Why not to use XP and Mac?
Why Linux Is better?