Marine Corps: In my limited experience with them I’ve found that they are truly amazing people. They know how to get things done with whatever resources they have available, they don’t make excuses, and very seldom try to shift blame around. This perception might also be colored a bit because they I don’t have much exposure to them.
I've met a few (ex) Marines, and that pretty much sums up the ones I know, too. Very talented, very responsible, very capable. Were I to be foolhardy enough to join the military, that's the one I'd go for, simply because of the immense amount of respect I have for these friends.