I like the subtle shape of #11, it makes it classy. Still, maybe the
gradient color is a bit too strong (I see in the SVG this is easily
adjustable)

Yep, that's easily done. :)

Mockup: http://schendje.fedorapeople.org/HackergotchiBadges/try4ribbon.png
Source: http://schendje.fedorapeople.org/HackergotchiBadges/try4ribbon.svg

I kind of like it like them like this, if I may say so myself. I want one for my own hackergotchi! :D

Jef