Well if you're going to buy a 256GB SSD, I would recommend you load your entire OS onto it
(unless you were planning on this
) and use your current hard drive as storage. Load the games you play the most on your SSD, and load other things onto your HDD.
However, if you don't have too many games you want to load onto your SSD, a 120GB would suffice for Windows, 4-5 games (given they're 3-8GB each), and some programs you frequently use.
But yes, the Samsung 830 series SSD's are very good
a few friends of mine use them and they're all very happy with the performance.