The/a (something) to end all (somethings) phrase
If you say that "a/ the something to end all somethings", you mean that something is the best, the most impressive, the most remarkable, the worst etc. of its kind.
I promise you your birthday is going to be the party to end all parties.
Personally, I think Tesla is the electric car to end all electric cars.
To win a contest or an argument
The best; with no rival
The origin of this phrase is not clear.
People tend to like forbidden or illegal things just because they are forbidden or illegal.
He must have believed that stolen fruit is the sweetest, and he, therefore, cheated on his partner.