The purest of pure GOLD tops off at 99.999% (0.001 is some other shit) AKA: Five nine! Therefore, something that is staight up, maxed out to the tits, top of the line is 'The five nine' or 'the 5 9' if you don't wanna spell that shit out.
Yo ma'fukka, check out this prime chronic I be rollin'. That shit's the FIVE NINE, nigga!
Oh my gosh, fellas! Look at the kaboose on Sally. I dare say it's five nine quality SHIT! Blah-DOW!
five nines, as in 99.999%, something that is the absolute best in category. better than anything else out there.
For a geek, "five nines" means 99.999% uptime for your server, less than five minutes per year. For humans, it's something that's just over the top good all the way around with a big exclamation after it.
To eavesdrop on someones conversation. Usually with the intention of taking the information for their own benefit. Comes from Penal Code 459 which concerns burglary and theft.