A little outdated but still a good one:
Four friends were climbing a mountain one day.
Each was from a different Big 12 school and each proclaimed to be
the most loyal fan at their alma mater.
As they climbed higher, they argued as to which one of them was
the most loyal of all.
They continued to argue all the way up the mountain, and finally as
they reached the top, the Wildcat hurled himself off the mountain,
shouting, "This is for KSU!" as he fell to his doom.
Not wanting to be outdone, the Colorado alumnus threw himself off
the mountain proclaiming, "This is for the 'Buffs!"
Seeing this, the Cornhusker walked over and shouted, "This is for
everyone" and pushed the Texas fan off the side of the mountain.