Halo: Combat Evolved. Warthog end run with shortcuts and easter egg where thirsty grunt says, "Good thing that food-nipple's waiting for me at the starship 'cause man, have I worked up a big grunty thirst!"

Also the hidden non cannon ending, only available on legendary level and some superfluous vengeance for Foehammer. A smoother end run on Halo CE with 360 at end gap. (less info)