She's just so wonderfully sarcastic
Zaf: Where's Jo?
Ros: Death by mascara. It was horrible to watch. Ruth's agonizing over the fact that there are no more horses in modern-day warfare and Adam's on a course learning how to lift his knuckles off the ground. So, you'll have to make do with me, I'm afraid.
Zaf: Shouldn't you be in prison or something?
Ros: This is the something.
She spots enemies from behind with a glass bottle and then kills them with a fork. A FORK.
(ok, you can't actually see the fork on the cap because it's so fast, you'll have to trust me on this: it's either a fork or a spoon. Which would make her even more badass)
She mocks the CIA liaison agent a LOT, and then shoots her in the leg and adds "Oh don't be such a cry-baby. It's only a graze with a 22". WIN.
The shooting and mocking
She has a real gift for small talk :
Lucas: Come on then, Ros. Small-talk me a little.
Ros: Okay... um, my perfume is made from the anal glands of cats. I read that in the paper this morning.
She rescues herself and then leaves her other team members with a "You two should work out more"
Her informant is dead and his computer can only be accessed by fingerprint recognition?
No problem, she'll casually bring you his finger (and you don't even have to ask)
McGyver has nothing on her. A makeup kit and some blu-tac, and she's all set to face a hostage situation.
She just gets the BEST lines. Ever.
"Congratulations, your testicles are yours to take home with you"
After winning a ninja fight in the dark with a Mossad agent, she just puts her hair back into place. As you do.
THE WALK. Yes, you're welcome. *stares some more*
(THE PRETTY IS OFF THE SCALE)
And a bonus reason, especially for meryl_edan: she looks VERY good in a suit/skirt