One of the biggest challenges in Bioshock are the Big Daddies. They roam throughout the game protecting the Little Sister. Naturally, the best way to kill a Big Daddy is by obtaining a lot of explosives, and that's precisely what Sam of Game Almighty does. This video shows how to create a very powerful explosive barrel used to kill the Elite Big Daddy in a matter of seconds.
Depending on the strength of the Big Daddy, you may need to finish him off with a few rounds from a shotgun.