I'd appreciate a little C&C on this set. Up until recently I've only really offered #1 as a style for business-type headshots.
The pretty-huge original size is there if you click through to Flickr.
Business Headshot Styles 2015 by nathancarter, on FlickrA few thoughts here.
First, and I know it's been subject to some debate here, but a headshot is a photo where the head dominates the image. Most of these are cropped too loose to be what corporations consider to be a headshot. That is not to say your clients might not like these crops, or that models, celebrities or high-dollar executives might not want something more creative and unique. But a corporate HR or marketing department generally has traditional views on what a headshot should look like.
The company I work for requires the head to be forward-facing, centered and approximately 2/3 of the image height, standard 4x5 vertical crop, with a white or light grey background. Pretty much standard passport photo requirements. This is because headshots are used for company ID badges, HR records and other identity systems, as well as on internal and, sometimes, external websites. I'm sure this will stir up another heated debate, but go to virtually any corporate website and look at the headshots they post of their board of directors. A few use head and torso portraits, and a few use non-traditional formats. But the ones that use headshots pretty uniformly use the traditional format I describe.
By all means you don't need to stick to the boring, traditional headshot recipe for all your samples, but at least some of the should show deference to a standard format if you're chasing corporate work.
The next problem, and please don't take this harshly, but none of these photos are attractive to me. The model looks unhappy and impatient, at best her smile seems plastic, and her head disproportionally small compared to her shoulders and torso. Her hair is good in some of the shots but in others it starts getting flat and finally ragged and oily looking in the B&W. This may well be the model's fault, but if this what you're putting out for marketing materials, potential customers are going to be justifiably fearful that their sessions won't turn out any better.
And do you really mean to imply that these are the only poses you do? It reminds me of my old studio days when we contract senior portraits, 4 sittings an hour, with fixed lighting and poses, at $10-25 per sitting. I'm not sure what your business model and pricing is for headshots, but I wouldn't limit myself to any specific poses. Instead, I'd work with each subject to produce a variety of poses and lighting (and crops) tailored to flatter the individual subject, addressing things such as broad or narrow shoulders, strong vs weak chin, double-chins, jowls, etc.
I suppose it boils down to what your business plan and pricing model dictates. But I'd be very cautious of limiting myself to a handful of poses and background options, and presenting anything less than my very best work, if I wanted to make a business of headshots.
flare added in post. 
