What is your usual strategy in stealth games?

You know, that reminds me... I've tried changing up my behavior in Metal Gear Solid (1), but no matter what I do, the dialogue remains the same. Damned if I do, damned if I don't.

Like at the beginning of the game
Guard: "He's killed three people?"
Snake: "There's an intruder besides me?"
Me: "Snake, you killed at least 5 people already."

Or at the end of the game
"It's because you enjoy all the killing!"
"I saw the look on your face when you did it!"