#5: Killer& Lady (Shadow Hearts 3)
Killer + Lady.jpg
Yes, I realize this one may seem like it's cheating because there are two names. But almost instantly after they meet, they do work together and thus I count them as a duo. Honestly, I couldn't find it in me to root with the protagonists in Shadow Hearts 3. They were all ... well ... boring. Even Shania didn't grab my attention too much and given she was made to be the first female Harmonixer, that severly disappointed me.
With Lady and Killer, though, I found myself wanting to root for them the entire game. And in fact, I cried my eyes out for them, both in the game and in a really good AMV I found of them. Disregarding the latter, though, they had a goal, set out to do it ... and technically won.
In fact, they would have accomplished everything .. if it weren't for the fact you play as the protagonists.
Also, they stay true to their personalities, up until the very end. This may sound incredibly lame but honestly, that task is much easier said than done to accomplish with characters. Most creators make people - villains especially - go slightly out of their normal traits and personalities. But with Lady and Killer, it stayed consistent and it gave a very genuine, sincere atmosphere around them.