Last films watched: The Story of Louis Pasteur (1936) 9/10 Dr. Strangelove (1964) 10/10 Killer Klowns from Outer Space (1988) 6/10 Manhunter (1986) 10/10 Evangelion 2.22: You Can (Not) Advance (2009) 8/10
Yeah, frame rate is typically going to be better then graphics, especially in multiplayer cases.
but in terms of single player... I think it can vary a bit from person-to-person on what one prefers as some might prefer to have better graphics and sacrifice frame rates a bit where as others would rather have a liquid smooth experience, if possible, and sacrifice the graphics some. you can tweak these settings on random games on the PC as usually lowering shadow quality is a way to have minimal graphics sacrifice for a decent increase in frame rate etc etc. I won't get into more graphics tweak details for now.
but as a general rule to give the average person a idea of how things are...
30fps (or so) = a enjoyable experience. 60fps+ = liquid smooth. a perfect experience.
with those general things listed... I would say one needs AT LEAST low 20's minimum as much under that for any length of time will be stretching playability of a game. even for those people who are really desperate to play a game I figure at least about 15-20fps as much under that it turns into a interactive slide show pretty much (i.e. not really playable and will definitely effect ones enjoyment of a game). but as a general rule... you want to have around 30fps at the minimum for a more enjoyable experience as that 15-20fps thing is for those really desperate to play a game and they can't afford to get new hardware for their computer like a graphics card upgrade etc.
and as you can guess... things scale up as you go from around 30fps to 60fps as you can see things start to smooth out as you climb up. like say 45fps, which is half way in between 30fps and 60fps, you can see runs noticeably smoother than around 30fps. but once you crack pretty much 60fps+ things are perfect and can't really see any difference beyond that (if there is, it's negligible for most people). also, for those wondering... fps is not a graphics thing, but a playability thing as once the frame rate drops below a certain point it WILL effect your enjoyment of a game because it prevents you from playing it basically as your trying to track stuff on screen with a mouse, like in a typical shooter game, but once the frame rate drops below a certain point it's going to handicap you for sure. but once that ramps up, especially in the higher frame rate ranges, things are much more responsive and easier etc, basically not sluggish as you can feel the difference.
NOTE: fps = frames per second.
p.s. hell, you can even see fps effect sporting events like say tennis... because a typical program (or movie) on TV is probably 24-30fps where as I have seen some events a while back and I could tell just from looking at the movement of them hitting the ball back and fourth that it was running at a higher frame rate as their movement and the ball ran noticeably smoother on screen vs usual and after checking the video file, sure enough it was.