I like all of these. I particularly like the 3D effect, subtle but very effecive, especially the slight gradience in the font since you chose a bolder one and the slight shadow below the graphic. Very hard to decide which one I like best. Interestingly, when I first saw the graphic it reminded me more of an 'S' than an 'i'. I wonder what it would look like with less slant to make it look for like an 'i'?
As I mentioned in my general comments, I would like to see a few wordmark submissions also.
As I just stated in my general post, I have decided against a 3D look, so I am moving #8. Thank you for your submission, however. It is very nice work.