I like the plain B&W the most. The sepia just doesn't really work for me there. THere isn't enough color variation to really make much of the color in 1, and the background color is kind of ugly.
With the color one, I think it probably needs sharpening, contrast, a little bit of burning on the paw sticking out.
Here's what I came up with:
lionb&w by
franklinrabon, on Flickr
not the greatest edit (considering I was working with the JPEG), but I think you get the idea. B&W are all about contrast and texture.