I don't know who voiced the british accent for female characters in faufau, but that voice was great, would love to have her as a voice option (I hope we will be able to choose between a few voices/races for character selection!).
I want to say it sounds a lot like Laura Bailey might have done that voice? Valla in HotS sounds very similar to it!
Grey deLisle (azula, li-ming from Diablo 3) would be so good aswell, especially if you ever do a character that is very vain and cocky, she does an amazing job and voicing that style of character.
Courtenay Taylor did an incredible job voicing the sole survivor in Fallout 4, is also the voice of npc's in ESO, new vegas, base ai in xcom enemy unknown.
Jim Cummings ... Pete in kingdom hearts, lorewalker cho, whole bunch of characters in bethesda games, do I really need to say more on how awesome he is?
Tony Amendola, probably better known as Bra'Tac from stargate also voices Father in fallout 4 and Khadgar in WoW, great voice for a Commander or general or the likes that might oversee our actions on Em-8er.
Keith Szarabajka, Apollo Diomedes in Dawn of War 2 expansion, almost every Dunmer in Skyrim (Filthy N'wah!), A whole bunch of Non feral Ghouls in fallout 4, I personally loved him in Universe at war as the leader of the bad guys Kamal Rex ^^
Honestly i couldn't care less about making it sound human.
If you can do a cheap robotic TTS (but cool robotic) in the game that could talk to me or NPC's i would be happy. I don't need a fully fledged human to speak all the words in the dictionary so you can make a sentence.