I have been woundering if other people have one setting in PS that they use to convert all photos to black and white, or do you use different settings for each photo?

Thanks!

If you have tried any B&W conversions in ACR with the "Convert to Grayscale" you will note that due to the individuality of each shot, the settings will become individualized for each shot.

Then when you play with the sliders to enhance each color's contribution to the final tonality that you are looking for, you will quickly realize there is no one setting that fits all....

hear, hear - just as you may shoot a scene from more than one spot (I often will shoot 10-15 shots at a very interesting scene), so each conversion needs its own time and conversion to bring out it's best values . . .
regards, tom