In future drivers NVIDIA will also be introducing TXAA. TXAA is a mix of hardware multi-sampling, custom high quality AA resolve and an optional temporal component. TXAA1 has a performance hit similar to 2xMSAA with quality above 8xMSAA. TXAA2 drops performance by levels around 4xMSAA while increasing image quality beyond 8xMSAA. Again, here are some examples.
TXAA is not available for us to test now but we can look at the performance levels offered by FXAA and MSAA as well as our own image quality examples.
Of all the results in this article the above image quality comparisons and framerates show the most clear cut win. FXAA offers better IQ than none or 4xMSAA and higher framerates than the traditional method by some way. The bonus is that by default turning on Anti-Aliasing in-game actually enables FXAA rather than MSAA.