I know of at least one more:  chesskia, who happens to be very generous with his time to help mentor those of us with lower ratings.

ok now there's 4.......

5; Manchero also is a diamond member

6 MackGarner (and a real nice guy as well.)

 seconded, a real gentleman

what is a diamond member

It's a $500-value chess.com lifetime premium membership.

See the memberships page for details.

 LucidDreamer 7

Any guy that has a gem next to his name.

DeepGreene 8

swordoflaban, eugene

go frank713!!! Hawaii people ftw!

*stares at everyone*...

I'm out~

9.malko

10) Polar_Bear

11) bondiggity

Good question!

 I'm a Diamond Member as well.

12) Warrior

13) jonnyjupiter

14) geolabious

ADK

15) HoldemRulzOK

 16) malko