Boom, Headshot!

Boom, Headshot is a phrase that rose to meme-status from a web mockumentary by FPS Doug while playing Counter-Strike: Source. It refers to the "boom" from the gun as the bullet ejects followed by Headshot, which usually means a one-hit kill in video games. The phrase was included in various other games, as well as dubstep artist Feed Me's One Click Headshot.