What is the minimum frames per second you find acceptable?

At least 30fps minimum.

It depends on how desperate I am, and how much I want to play the game.

When my computer is brand new, and state-of-the-art, I'm a lot less forgiving of a game, and don't like it when a game, any game, dips below 30fps. If my computer is on its last legs, on the other hand, then I'll put up with 15-25 fps, if the game doesn't demand smoothness.

Neverwinter Nights 2, for example - I must've played all the way through at about 20 FPS.

40 - 50 FPS

I know most people bump graphics settings in games up to maximum, then just live with whatever FPS they can get... but if you're getting lower than 30FPS, swallow your pride and turn those settings down. Having a good FPS is far more important than a little more eye candy.

FamiBox