Originally posted by Nephthys
Also Manshep sucks dick.
Don't be jelly just because Mark Meer's Shepard is ten times the Shepard Hale's Shepard is.
Mark Meer da bess.
Hale may be a good voice actress (Though really, her talent gets blown waaaaaaaaay out of proportion, you'd think she was ****ing Frank Welker based on the hype she gets), but her performance as Shepard was not so fresh, like dat Mark Meer's was.
Anyway...
The Boss from Metal Gear Solid 3: Snake Eater is the only correct answer.
http://media.photobucket.com/image/the%20boss%20metal%20gear%20solid%203/MateuVTK/Metal%20Gear%20Solid/Metal%20Gear%20Solid%203/TheBossTheJoy.jpg?o=4
Not just because she at no less than three points hand Big Boss his ass. Not just because she is the strongest combatant in a team of supers while she has no explicit superpowers (Disregarding her husband, the Sorrow, post-death he is the most powerful character in the series). Not just because she managed to, through badassery, intimidate Volgin, a seven foot tall man with super strength and ten thousand volts of electricity pumping through his veins (He is also the main antagonist). Not just because she was badass enough to fight during D-Day while nine months pregnant, and proceeded to have a cesarian section during the battle. It's not just because she practically won WWII for the Allies.
But because she also, more than anyone mentioned here, has integriteh, and is a completely selfless, yet tragic hero, in every sense. When Volgin ****ed up the original plan of America to acquire the Philosopher's Legacy via nuking his own country (Technically the issue is more complicated than that, but I'm too lazy to explain why), The Boss received her new orders: She had to play the villain, and be killed by her brightest apprentice who is practically a son to her, all in the name of preventing Nuclear Armageddon. Not once did she falter from this task, not once did she betray her country, or the principles that she believed they stood for (Even if her country was not as noble as she believed, that is part of what makes her so tragic), her own noble principles. Integrity, loyalty, and unwavering valor in the face of death. That, now that is truly badass.
I'd be hard-pressed to find anyone, man or woman, more badass than The Boss in gaming.