IMHO, this was a great thread.
Turning a bunch of PS'ers loose on a raw version of a portrait of a photogenic subject is probably one of the best ways to discern artistic preferences, techniques used and possible equipment limitations, specifically, lack of hardware-based monitor calibration.
For example, in terms of styles and artistic preferences, Chris seems to always turn out portraits with refined colors and effects, opting for the minimal changes needed to produce understated but gorgeous, very believable images, whereas I usually go for more dramatic efx (more PS'ed makeup, taking more years off of older subjects, etc.). IMHO, PseFrank turned out a piece that would have been the envy of the artists working for Playboy back in the 60's and 70's - youthful, three dimensional, vibrant, natural colors.
I love the highly stylized result of Hawkeye. For the right end use, it would be a surefire winner. The B&W high key sketch of Hoogle is yet another fresh look at the subject.
With respect to specific techniques that were used, I see examples of added skin texture (...can be a very useful ancillary technique), as well as skin smoothing using a Gaussian blur on a separate layer (almost always a bad idea because it tends to oversimplify the structure of the skin and the face as a whole).
With respect to equipment shortcomings, I see a couple of examples where the colors are just so far off (eg, too orange, too magenta) that this is unlikely to be a stylistic choice, but rather, probably arises from these individuals performing their edits on a system with an uncalibrated monitor or in an environment with uncontrolled changes in ambient lighting (eg, taking their laptop outside on a nice day ;-) ).
Knowing the work of other individuals, I think I also see examples in this thread of people demonstrating the most needed improvements (eg, brightness and contrast), but intentionally (ie, because of lack of time or interest) not devoting time to working on other aspects of the image to produce a more finished look. I have absolutely no problem with this and do it all the time myself.
Anyway, that's my take on this wonderful thread.
Cheers,
Tom M