Civil Security Ghost. Cause it's green which makes it look decent enough. All thus other skins are just meh, especially the proxy ones. (Personal preferences) hypes for PB2.5s skin editor.
I like mostly the Marine without helment (With that black thingy he wears on his head.), cause It looks like real life spec ops soldier with the addition of a futuristic exo suit.
Also I liked Blue civil security lite, just looked cool.
I really like the blue Civil Security. Blue color reminds me of the sky and the sea, so exciting, yet relaxing, and it looks great on almost any other skins. Perfect!