For a large chunk of PC games these days, the antialiasing options on offer are far more complex than a simple binary choice. Whether it’s FSAA, SSAA, MSAA, MLAA, FXAA, or a myriad of others, the choices can be bewildering. In general, you can expect the more demanding antialiasing solutions to provide the better results. It’s not always as simple as that, and some forms of antialiasing are just too expensive for the image quality improvements they provide - as anyone who’s tried to lurch through with 8xSSAA and attest.
Just wrapping your head around what they do is a task in itself, and it seems as if the likes of Nvidia and AMD keep finding newer and more efficient ways of handling the task. At a base level antialiasing is a means of making the images rendered by your GPU sharper without increasing the resolution. All forms of AA use various techniques to blur edges and reduce the appearance of jagged lines. [More]