9000 (Number)

9000 is the ultimate checkpoint in Numbers. It is the highest you will ever go, because everyone knows 9001 was only achieved once.

Origin
In the Dragon Ball universe, Vegeta found out that his power level was OVER 9000!!!1!!1 Thus, 9000 was added to the Numberbet as the ultimate checkpoint, and 9001 as the only number above 9000.