clearly something is different... it's not the same shot with 3 different photoshop jobs applied... they're different shots and consequently, they all have a different feel and probably different settings when shot (unless you shot them all in manual mode with the same settings)
that aside, all of the images lack a point of interest. i wonder if color wouldn't be better? composition wise, i'm not feeling it.
if you're only questioning the contrast and darkness of each photo, the 3rd one is too bright, the first and second ones are ok, depending on your intent. the first one appears too dark (unless you wanted to silhouette the trees in the marsh) and the 2nd is pretty good if your intent is to show more detail in the trees in the marsh.