22fps is what the human eye sees as natural motion. The two extra frames for film (24fps) are added in in case a frame is dropped during broadcast. The further above that you go the more the game looks like it's put on fast forward (People with VHS should remember what this looks like vividly). 60fps for gaming is a nice sweet spot because you're not that far ahead of natural motion and not too far ahead for it too look like it's getting sped up. This is more useful for gameplay especially when you need it for reaction time. On the flip side; your eyes will adjust to 60 fps and it will eventually seem like 30fps anyways so it doesn't really matter. Though going back to 30fps after will look as weird as something in 60 until your eyes re-adjust.

Got any sources to support this point? I never used to be able to distinguish frame rates until Dreamcast and  since it clicked what the difference was, I can now tell 30fps and 60fps instantly. Have been able to since wondering why Metropolis Street Racer and Sonic Adventure 1 had a double vision effect when your view was turning, but then games like F355 challenge and Sonic Adventure 2, the movement was flawless.

I really wish 30fps did look like 60fps, but it just doesn't. I'd also disagree with "fast forward" as the movement is still happening at the right speed. Does life look like it's in fastforward to you? that has infinite frame rate refresh ;)

constant 24 fps is enough for me.

A motion blur solution for helices, and is enough for me.

Other than the 22fps, I have no sources other than what I've observed.  I play my Final Fantasy 8 on emulators to get texture filters and such.  One thing I would do is unlock the framerate when I'm grinding.  Framerate would get up to and over 100fps.  It literally looks like I put the fast foward on.  As far as eyes adjusting to 30, this goes to CGI-Quality as well, I'll explain my experience.  I noticed this first with Marvel vs Capcom for PSX and putting the speed to the max setting.  It would be blazing fast, not quite sure what the framerate is, but it'd be so fast, again like it's fast forwarded.  After playing at that speed for a few hours I'd get used to it.  I would get so used to it, it would seem like it was back at the normal speed.  Until I'd go put it back to normal speed and it was too slow until I would get used to that setting again.

24 fps is for movies. The difference u will notice between 30fps or 60fps in games is that playing after 2 hours the motion-sickness comes around the corner. Some people will not have this problem but the majority are sensitive for this. The higher the framerate, the better.

Are you sure the game isn't speeding up because you're increasing the frame rate?

It's seems more like you're seeing the core speed of the game increasing. environments move as fast at 60fps as they do at 30fps, it's just that there are more frames so for example:

30fps

1 3 5 7 9

60fps
123456789

Core game speed increased

1357911131517

If that makes sense. Increasing the core speed, means when at 30fps or 60fps regular speed, you'd be at 9, what you're getting in the emulator by speeding it up is 17 in the same time making it seem like it's being played on fast forward. So yeah, your emulator really is speeding up the game, rather than increasing the frame rate.

30 fps is playable 60fps is superior thats all there is to it.

I target 60 fps.

What I'm trying to get at, is playing at 60fps or higher, you'll eventually get used to it.  True test to say though, is if you go to a game not knowing what the framerate is.  You'd be hard pressed to notice what it really is.  Case in point, Vanquish is one of the most smoothest games out there, yet it does it at 28fps.

30 or higher is fine, anything higher than 60 is probably unnecessary, I don't think I can even comprehend anything higher than 60fps