I love how in GTA games the replay function lets you make a video over time and it turns out beautifully because it's not rushed at all
GTA 4 records positions, speeds, amount rendered, etc. It's beautiful because you can move around in the scene, change angles, audio levels, and speed it up/slow it down and adjust the number of frames rendered accordingly.
These videos would be completely different if GTAIV just recorded like FRAPS.