@Brutaka - I don't think it's altogether that easy to discard skill level when looking at the designs, as (very) generally speaking, when it comes to drawing faces/characters, more skill = more detail, and more detail = better design. Because of that, I'd say my favourite is the last one, though whether that can be attributed to actual superior design or just superior drawing skill is very, very difficult. I've tried looking at all four impartially on a design basis, but like I said, it's difficult to when there's such a divide in quality of shading/colour/detail. The fact also that the character in the first two has her eyes closed makes it even more tricky, as the eyes in the last two really do add to the feel of the piece (you do lovely eyes). But yeah, it's entirely up to you, I'm just rambling.
I suppose your right... Hm... Maybe if I make a sketch with the four designs next to each other, all drawn at my current skill level...