"antialiasing quality, anisotropic filtering"

What does this mean? Do you want high or low if you trying to get the highest graphics? I'm sorry, but I'm just used to High/Low Graphics easy-mode settings.

Higher for better quality graphics.

Lower for more FPS.

So 16x is better than 8x.

Anti-aliasing smooths out jagged edges, but can be quite a big performance hit depending on your screen resolution and graphics hardware. The higher it is, the smoother edges will appear, and this of course comes at the cost of lower FPS.

Anisotropic filtering reduces the blurriness that appears in textures when viewed from an acute angle. Again, the higher it is, the less of this blurring you will notice, and the bigger the performance hit will be.

Examples and more information:
Anisotropic filtering
Antialiasing