Not sure if I've really seen many (if any) Borderlands customs, but here's Zer0 from Borderlands 2! I'd had the recipe for this dude dancing around in my head for the last couple days, and it only took me a couple hours to put him together. Snake Eyes body, katana, and gun, Marvel Universe Series 1 Iron Man head (with a bunch of sculpt), and some other sculpted details. The last picture is just some iPhoto effect that had a passing resemblance to the cel shading used in the game.

Thanks for looking!