LS gets my vote today.
why? its akira, akira is my fav alltime anime! ;O
well, i wubs it, but there are more reasons for that i can assure. the first is the choice of such a legendary graphic, he did some good tinkering to blend it in with the great background, the multi-angle building BG works immensly with the theme, and of course, a fitting colour palette, red suits kaneda's biker suit and his uber bike, and of course the font choice is very fitting indeed :O
Kuwa's sig also is teh uber, the brushes blend in with that stock very well indeed, combined with a great choice of text. but it misses somthing for me, its uniqueness, the cold blue theme just dosnt keep me enticed, looking at the image, i saw more to a dark purple or a rougue D:
overall, when i see LS's sig, i see passion and uniqueness, i see the same in kuwa's sig, but it just misses that sharp edge with the colour theme for me