Well, lets see...if I said give me the first thing that pops in to your head when I say "Nintendo" a lot of people say "Mario" so lets see what I have to say and others give their INITIAL response to this:
Nintendo - Mario, Zelda, Pokemon
Sony - Final Fantasy, MGS, Tekken
Sega - Sonic and his pals
Blizzard - Starcraft
Bethesda - Fallout
Namco - Pacman
Eidos - Lara Croft
Xbox - Master chief - Cortana
Your argument BoB that S-117 had no personality is quite valid, he had some it wasn't very open what I seem to remember going back to halo 1 - 2 and 3 (apart from omfg this is AMAZING!) is Cortana's wonderful personality, she was sarcastic, sassy about things for a character who supports you by opening certain doors, informing you about the enemy battle plans ect she does it in a very human way she's kinda like "oh great we're gonna die you know what chief, let me get this"