How I Would Have Ended BioShock - a post on Tom Francis' blog

End scene: You, as a Big Daddy, standing motionless as the water rises time-lapse fast, everything zipping in motion-blur streaks around you. As soon as our view is underwater, everything goes silent and slow. The body of a little sister drifts slowly past behind you, its back to us.

When all is still, Fontaine suddenly scrambles into view, thrashing spasmically, screaming bubbles, clutching his throat, red in the face. After some violent jerks, he lies completely still.

A few seconds pass, then a light flicks on in the background. We cut to a close-up of it: the Vita Chamber doors slide open and Fontaine bursts out again, screaming bubbles louder and louder as he thrashes towards us, and his terrified face almost fills the frame before we cut to black.

Obviously this needs to be re-rendered a few different ways:

Without you, if you got in the bathysphere and escaped.
Without the Little Sister body, if you saved them all.
With your body, if you died in the final fight.