What shader should i use to counter oversharpening?

 I've been using Gaussian Blur to smooth out the visuals of an extremely oversharpened and noisy looking game, which works ok. I've found that Denoise and Surface Blur do a similar job but i don't know which is better to use. Any recommendations?

Update: I think Surface Blur looks the best of the three.

Try using CAS.fx with sharpening amount set to a negative number.