Space Marine armor customizations

So, the setting I'm trying to develop is the result of throwing Contra, Aliens, and Starship Troopers in a blender (with a splash of Star Wars). The armor the characters wear is genetic offspring of clone trooper and Spartan armor. In other words, it's got a few minor abilities, but it's hardly Tony Stark's rig.

The thing is, I thought one way to make the characters a bit more individual is for them to have made some personal customizations (cosmetic, not technological) to their suits. Any suggestions for slogans, images, etc., and/or where they'd be on the armor?

I think we actually have a trope for this somewhere, but I can't remember where. I'd recommend naked women/men depending on preference of the driver.