Wow.. lets bring in some old facts.
Its rare/hard to see over 60 FPS. TVs and Movies knew this for the longest time, hince why everything the have is 30-50 FPS.
More FPS is a "Smooth animation" however sometimes you don't WANT smooth animation- you can make objects move FASTER by having less FPS. Think about cartoons. If everything was drawn in 60 FPS all the time, throwing a ball would move the same rate as shooting a bullet. You skip "frames" to make objects "move" more quickly.
Games is very open. 30 FPS in Crysis is fantastic, even 30 FPS in counterstrike is decent. LAG comes from other things, and your resolution matters a lot in Games. Some games work better on low/medium resolutions, some actually work better on Higher resolutions and some games don't care what you play it on.
The rest of your computer is just as important as the GPU, if your RAM or CPU are slow, your game will stutter no matter how many FPS it tells you it's getting.
The general golden rule of FPS is this.
60-70 FPS is golden, any more is just icing on the cake. Getting a 150 FPS you either have a MONSTER computer, or, your playing a very old/simple game, and rarely will you even notice a performance change with 70+ FPS. In most games you won't notice a change between 40-70 FPS at all. (some games do break this rule, however, it's a good general rule to have)
