The badge icons on SO are kind of sucky. I'm talking about the ones at the bar at the top of every page next to your username. I just earned a gold badge on Programmers, and the icons are really distinct and colourful, and have nice shadows. Gamedev has much easier to distinguish ones as well. On StackOverflow, they're kinda, well, flat and meh, and more importantly, the gold badge blends in way too well with the background. I'd appreciate something more distinct and three-dimensional. Right now, my eyes easily glide over especially the gold badge icon.
I'd recommend a voice over on hover as well:
(Why limit yourself with a visual improvement)