There's no absolute best. There's only the best for a person. If XP SP3 is best for you, so be it.
But you shouldn't try to install it on the latest laptop if the maker doesn't provide XP compatible drivers. Then you risk the USB or the WiFi or the touchpad not working. Then certainly it isn't the best.
Recently I switched windows XP to windows 7.
with my experience windows XP is the best operating system that I have seen as of now.
what's your opinion. Please share your views.
Vinay Naidu Gali.