"Great" and "Script Kiddie" just don't feel right going together heh.  It's a hard thing to really say who was the greatest of any of the other catagories though.  I always loved John Draper's handle, though last I heard that phreaker was living out of a van somewhere... how sad is that?  Some of the more entertaining hacks I've seen, are like the hack of the screens at a M$ conv showing up with penguines.  That was pretty cool.  I suppose you could point to Linux itself as being kind of a pivital 'hack' of Linus's Kernel and the GNU OS framework.  Infact, the inherent moldability and openeness of the project and it's constant 'evolution' due to 'hacks' by hundreds of thousands of developers and hobbiests is pretty cool. 

I think that's all I'm going to submit to this one though for now.

1. My top spot goes to the starter of this Usenet post, who got fed up with an OS that cost money and didn't work the way he wanted it - so he wrote his own OS.
2. Fyodor.
3. Antirez.

nice, and all have been to jail...

for current ones...

solar designer
holy father
metasploit core developers the guy that wrote the meterpreter stuff (skape i think) that is some mad kung fu