Must 'completely free' mean 'hard to install'?
Of course not, but that's beside the point, because if you don't want to be bothered with the installation part at all, as most casual users won't, you just go and buy a computer with Linux pre-installed, as you would with any other OS.
The KDE Slimbook is hard to beat in terms of polish, raw power, price and convenience. Other brands are also available.