Good test GuGuProd but if am not mistake (some one correct me) for recording raw the best is using native ISO. 100, 200, 400, 800, 1600...
The ISO question seems to be one of the hardest to answer... still, after a shitload of research and different opinios. I´m not sure if this one is still correct, but it was the most accurate when i tried to find the best iso the last time.
For a long time we believed Iso values like 100 200 400 800 and so on were the best.
Then someone discovered that a multiple of 80 was best. Iso values like 160 320 and so on.
Turns out, the real native Iso values were just in between, not accessable for the average user.
Thats why ML allows you to dial in (negative) digital ISO...
-----> According to this the best Iso values are Iso´s 100, 200, 400 and so minus one or two EV digital ISO
gosh, just started a new thread for RAW only and we are already going off topic
Hope the information im giving you is correct.