Here in the UK, the frame rate for films/TV is 25FPS, and in the US, it's 29.7FPS.
I think in all honesty, the US got the frame rate more or less right, whereas in the UK, I think they were a bit off.
Yes, 25FPS tends to be smooth, but if you are watching fast action, especially if a camera is panning about, I do notice jitters in the motion.
TV's are around now though that smooth two frames together (100hz scanning) so that the frame rate becomes around 50FPS to the eye.
Games are different though, since you are playing them, so you expect fast feedback from on screen actions. I'd say 30FPS is acceptable. Anything below that, and you aren't getting the experience, the developers wanted you to get.