Graphics. Does AA make a big difference?

[derekx]

2x makes a huge difference with minor performance impact.
4x makes a decent difference, a bit higher of performance but not too bad.
8x you probably won't even notice, but it takes a lot of performance.

Pictures are hard to show it because you notice a lot of it in the motion and animations.

Aliasing is more noticeable on still images. You will see it better in stills that when the game is in motion.

Here's a random guide: http://www.tweakguides.com/Graphics_11.html