|Love that long-necked Spiritu Sanctus.|
Pope Saint Gregory VII is considered one of the greatest popes of all time -- no bunk. He was a tremendously courageous reformer, working to stamp out simony and clerical incontinence. Those are old-timey terms for "buying and selling offices in the Church" and "priests getting laid."
The former was just bad all around. No reasonable person can defend it. He wasn't the first to take a stand against it, but his reform had legs. It may have touched off an anti-pope crisis in which the Holy Roman Emperor Henry IV backed a false pontiff named Clement III, but that in turn led to papal elections by the College of Cardinals. That system may be more oligarchic than democratic, but it is a lot cleaner than a system where the strongest king in Europe picks St. Peter's successor.
If you want, you can read more about him at wikipedia and New Advent. I gotta bounce.