The *real* members of SL's Top 10 Power elite are...

Zeppi Schlegel - SL would have a very different business environment right now if it weren't for him.

I would say criteria:
- Does more than just one thing. (So that rules out anyone who may just sell one type of item or is just a socialite.)
- Has significant sway over public opinion and organizing events / other
- Has made major achievements that contribute to SL as a whole
- is still currently active in projects (I can think of many who used to be on this list)
- is not a Linden (because c'mon, then the list would be mostly lindens)
- innovating SL

Criteria that really don't matter so much:
- makes $
- knows people (who doesn't?)
- is famous in the real world


Naming names... 10 who meet the criteria

Aimee Weber
FlipperPA
Anshe
Fizik
Cristiano
Walker Spaight
Katt Kongo
SNOOPYbrown Zamboni
Reuben Tapioca
Gwyneth

And of the people on the list, there are another dozen or so I can think of that could easily jump to the list and another dozen who would have been on the list if you asked 6 months ago but have become inactive.