Whats easier to correct in PP

Which photos are easier to correct in PP?

Underexposed or Overexposed?

As long as there's no clipping, overexposed is better. Underexposure leads to more noise.

There's a heck of a lot more latitude to fix underexposure than overexposure, but the noise is a killer, as René said.

And the corollary from the two posts above is that if the subject's tonal range is greater than the camera can handle, i.e. the histogram is spiking at both ends, preserve the highlights by lowering exposure until just before the right side spikes. You will sacrifice the shadows, but in PP you will find that you can pull them up a bit (more so in RAW than jpg).