The Double Turn?

I was watching the Bret Hart biography thing:Wrestling With Shadows and he talked in depth about the Double Turn during his match with Stone Cold back in like 1996(pardon my lack of information as I wasn't watching WWF back then so). So I started thinking and I'm like when was the last time that happened? What was the most successful double turn? It would probably be the Bret/Austin one being as it established the biggest star of the Attitude Era and helped start it(didn't it cause Bret to want to change his character being as he was a heel being booed for having morals).



So my 2 questions:



What are some examples of double turns in the 21st century?



And



What is the most successful/impactful double turn in wrestling history?