I'm diggin the bright kandy green. It seems like you can see the shadows better. Or maybe it's how you did the lime green one. The lime green looks a little like someone had a few too many mai tai's and puked. But, in a good way.
Actually, I like them both a lot and I haven't seen a lime green color like that before.
Hmm... Usually I enjoy the more toned down earthy colors but when it comes to green I'm a fan of the left one. Very nice shade of green. And are those some kind of leaves or something behind the left skull? That's a nice touch!