To me, [name_f]Natasha[/name_f] has a strong, independent feel, international and solid. [name_f]Natalia[/name_f] has a similar vibe, but maybe with added flair.
Some names that give me a similar vibe:
[name_f]Frederika[/name_f] (nn [name_f]Freda[/name_f], [name_u]Freddie[/name_u], [name_f]Rika[/name_f], [name_f]Kiki[/name_f] etc)
[name_f]Anastasia[/name_f] (nn [name_u]Nat[/name_u], [name_u]Nata[/name_u], [name_f]Tansy[/name_f], Tasia)
[name_f]Henrietta[/name_f] (nn [name_f]Hen[/name_f], [name_f]Henny[/name_f], [name_f]Etta[/name_f], Rett, Retta)
[name_f]Angelika[/name_f] (nn [name_f]Nika[/name_f], [name_f]Annie[/name_f], Ange)
[name_f]Elizaveta[/name_f] (nn Veta/Vita, [name_f]Liv[/name_f], Eli)
[name_f]Irina[/name_f] (nn [name_f]Rini[/name_f], Riri, Ira)
[name_f]Antonia[/name_f] (nn [name_u]Nat[/name_u], [name_u]Toni[/name_u], Nia)
[name_f]Veronica[/name_f] (nn [name_m]Vero[/name_m], [name_m]Ron[/name_m], Vronky, Nica)
[name_f]Larisa[/name_f] (nn [name_u]Lacy[/name_u], Ris/Reese, [name_m]Lars[/name_m], Lissy)
[name_f]Roxana[/name_f] (nn [name_f]Roxy[/name_f], [name_f]Roz[/name_f], [name_u]Rocky[/name_u], Ana)
[name_f]Alexandra[/name_f] (nn [name_u]Sasha[/name_u], Xandra)
[name_f]Valentina[/name_f] (nn [name_u]Val[/name_u], [name_u]Vale[/name_u], [name_f]Vita[/name_f], [name_f]Lena[/name_f], [name_f]Leni[/name_f], Len)
[name_u]Valentine[/name_u] (nn [name_u]Val[/name_u], [name_u]Vale[/name_u], [name_m]Len[/name_m], [name_f]Leni[/name_f], Tino)
[name_m]Nikolai[/name_m] (nn [name_u]Niko[/name_u], Kai)
[name_m]Leonard[/name_m] (nn [name_u]Leon[/name_u], [name_u]Leo[/name_u], Ned)
[name_m]Maximillian[/name_m] (nn [name_u]Max[/name_u], [name_m]Maxim[/name_m], [name_u]Miller[/name_u], Mills)
[name_m]Simon[/name_m] (nn [name_u]Sonny[/name_u], Sy)
[name_m]Sebastian[/name_m] (nn [name_m]Seb[/name_m], [name_m]Bastian[/name_m], [name_m]Baz[/name_m], Bash, Eb)
[name_u]Adrian[/name_u] (nn [name_u]Ade[/name_u], [name_u]Rian[/name_u], Addy)
[name_m]Leonce[/name_m] (nn [name_u]Lee[/name_u], [name_u]Lonnie[/name_u], [name_u]Lennie[/name_u], Leo)