Slice has had six different versions of his figure made, and only one is not totally embarrassing. The first two were about 90% cool, with the red color scheme and the fencing mask (don't underestimate how intimidating a fencing mask can be), but with a stupid leopard print on his pants. The later versions were even worse, dropping the mask and red and making him covered in padding and with little sunglasses that look like he's going tanning. Still, he bases his martial arts on the movements of scorpions, which ups him a couple places in my rankings.
Cobra, for all its internal problems, has never had an issue with hiring women. If you want to do evil, and don't mind the occasional rally where you stand at attention and listen to a man dressed as a snake yell, you can do pretty well. Vypra is employed by Cobra, but also, according to one of her filecards, is also the protector of a forge where ninja swords are made. Despite her martial arts skills, Cobra has her driving a jeep. Really.
2) Storm Shadow
1) Snake Eyes
The US military took a big risk in hiring a ninja who doesn't talk, doesn't show his face, doesn't follow orders, often goes off on his own without telling anyone what he's doing, and has a shadowy history with dozens of now-criminals. He's still the most popular member of the team, with lips or without, and brings shadowy ninja expertise with him on every mission. But he's more than just a strong, silent master of the katana blade: as the above clip shows, he's also a breakdancer. Man, that show was weird sometimes.