I'll try to explain to you what people are expecting from this thread and why they're getting disappointed with what you've been doing.
Look at the following examples.
http://fav.me/d39t7z4
http://fav.me/d3a4t3g
http://fav.me/d3aajwg
http://fav.me/d3a6pz2
And in case you would only like to look at anime-like pictures, compare the following:
http://fav.me/d3834ao
http://fav.me/d39dr8s
http://fav.me/d393lof
That's the kind of things people expect to see when they're asked "which style should I use?". You can see many differences in how things are drawn (leaving the coloring alone), the proportions, the thickness of the line, how each part of the character is drawn, how long or thick/thin the legs are, for example. That's what we call 'style'.
Compared to that, the problem is that you are basically just changing the iris of the eye and probably making subtle changes on the rest of the picture, calling it a different style altogether. The most changes I can see you're doing is the inside of the iris on the eye of the character, but the rest looks pretty much the same, really. At least it is the expected amount of difference between one drawing of a character and another when you're not animating something and you're not a more seasoned artist.
If you want to get feedback about the different kind of irises on the eyes of your characters, maybe you should just draw a bunch of eyes and ask which one we like the best? When I'm in doubt with eyes, or hair, or, idk, noses, I usually ask directly "what kind of nose works better?" or "do this picture look better than this other where I drew the eyes higher?" and get better feedback. Maybe you could do something like that too?
By the way even if you say your drawings are inconsistent with each other, the fact a lot of people say they look pretty much the same means that maybe you're nitpicking too much on your own style C:
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EDIT:
http://fav.me/d2oghla - This style meme is fun, the links of some people that have done it at on the artist's comments part (the one I like the best is this one
http://fav.me/d393x17)
When drawing something, anything, USE REFERENCES!! Use your Google-fu!
Don't trust your memory, and don't blindly trust what others teach you either.
Research, observation, analysis, experimentation and practice are the key! (: