Moghedien is one of only two Forsaken to survive Tarmon Gai'don. [She has an adam placed around her neck by a Seanchan suldam.]
Hessalam is one of only two Forsaken to survive Tarmon Gai'don. [She (Graendal) has a compulsion weave backfire and is under Aviendha's control.]
So, that's two. But then there's:
Egwene finds Mesaana alive in the waking world as "Danelle", but reduced to a childlike state and soiling herself, her mind having been broken. Unable to respond to summons, the Dark One considers her to be dead.
What happens to her after TGS? Does this then make three rather than two?