The last one is the best of the eight, but I'm not a particular fan of any of them.
I would scrap any design that uses such a bright green for a background. That's just distracting. And the green you use for the brown versions isn't particularly attractive.
EDIT:
I took the Green from Mexico's flag and the maroon as one of the default colors from paint. Maroon, a brown with red hues, goes really well with this more subdued green, making for a much more aesthetically pleasing color combination IMO than anything you've posted so far.