Geralt can be considered just as much of monster as Letho if you look at things in a different way.

But yeah, great analysis there. Letho is a great three dimensional character. It's great to have villians that aren't just evil.

If Geralt had his memory and knew who Letho was, do you think the story of the game would have panned out significantly differently?

I believe Letho answered that did he not?
By saying that he was afraid Gerald would identify him in the Solar when he arrived there with Foltest to claim the king's children.
Given that fact alone, Foltest would have been still alive... and that is a very significant change.

letho certainly does have a very distinctive voice.

I chose to let him live after I finished the game two times(Roche/Iorveth and saving Triss both times).

The reasons I let him live are:

- is that he took care of Yennefer,even though she had amnesia.He could of just let her die in stead of taking care of her.

-spared you in you're first fight with him.Pretty good reason to forgive.You would be dead if not for his "mercy".

-he just wanted his school of witchers to be rebuild and go to any lenghts to achieve this goal.I wonder how many of us did the same just to save Triss(I would of murdered anyone to save her).

-witcher's code implies to never kill one of you're kind,even though Letho already stated that he wasn't a witcher anymore.But we all know that he is still one on the path.I spared Berengar for the same reasons.

These are few of the motives I think it was a good decision to let him live.

To me, it was a hard choice, but I chose to kill him to honor the promise Geralt made when Roche saved his life--twice in my game. The second time came after choosing Iorveth's path. Geralt was captured and only the quick actions of Roche and Ves saved the day. The promise was expicitely renewed at that final meeting.

It wasn't a pleasure to kill a one-time friend and fellow Witcher by any means. The kill was easy and unnecessary, which added to its pointlessness.