nVidia/AMD - Proprietary/Open-Source Drivers?

[Jesse Palser]

Hi,

I installed Kubuntu 14.04 L.T.S. 64Bit onto two different desktops.
I am confused about proprietary and open-source display drivers.

On my Intel/nVidia desktop, after the O.S. is installed I am prompted to 
install
nVidia proprietary display driver which I do and all is well.

On my AMD/AMD desktop, after the O.S. is installed I am NOT prompted to 
install
AMD proprietary display driver?

So everything is good on the Intel/nVidia desktop, but not on AMD/AMD 
desktop.
Are the AMD proprietary display drivers bad?
Are the open-source AMD drivers OK?
(can I play 3D Windows games under WINE?)

Just a little confused, please advise...

Jesse