"No'ach found favor in the eyes of Hashem". What does this mean and why?
Targum Yonasan: Hashem favored No'ach over the other people of his generation, because he was a Tzadik. 1
Ramban: The term 'Chein' implies that everything that No'ach did was nice and pleasant (like we find in connection with Yosef and Esther), and made Hashem happy. 2
The Torah is relying on the following Pasuk, where it describes No'ach's virtues in more detail (as the Ramban points out).
In contrast to the other people of his generation, who made Him sad (Refer to 3:6:1:4), as the Ramban explains.
No'ach, Daniel and Iyov, were great Tzadikim, yet they did not merit to save their children, because they failed to teach the people of their respective generations how to serve Hashem.