what chord progression do you think is most overused (also an unrelated question)

If you consider music beyond rock and metal...it's been done...consider all the experimental and avant-garde artists...there are only 12 notes in western music...me thinks, odds are, it's been done.
 
@holytonescale:

"chord progression" only refers to the harmonic movement...it has nothing to do with rhythm, but what you were trying to say is correct enough.
 
But there is an infinite amount of harmonies anyway:p The odds therefore are, not all chord progressions have been used.