Kay, MGS4 is out in a few days and I am officially in Metal Gear Solid fanboy fever right now. I am just about to finish MGS3: Snake Eater and I have to say, through all the games so far The Boss is by far my favorite character.
She was tougher then nails (beat snake up about 15 times during the game), cool, collected...and frankly Hot as hell. When she is in the white sneaking outfit...wow. her story segments were the best in the game...by far.
Seriously her actions and words were uniformally amazing, she is a credit to Kojima in her character being much more then an Eva or a Merryl ever was.
I hope MGS4 has similar quality female characters, Meryll could be I suppose, but her history isn't nearly as tragic as the Bosses.