For Season 8: I think the judges always chose the more popular act whenever they avoided a tiebreaker.
For Season 9: I believe Mike Super had more votes than AcroArmy in the quarterfinals. Mike turned out to be a strong wildcard. AcroAmy's popularity skyrocketed in the semifinals. Also, Smoothini definitely had more votes than Christian Stoinev.
For Season 10: Samantha Johnson won the Dunkin Save by a wide margin. The Gentlemen *may have receieved more votes than Alondra Santos but it was close. Alondra is a very lucky girl to make it this far. Idk about 3SoB vs Freckled Sky, very close in the Dunkin Save. Daniella last night likely had more votes than Benjamin since she was very close to Gary in the Dunkin' Save.