Did Ryuk like Light?
Ryuk was basically an insert for the audience.
finding him entertaining as all hell in his grandiose goals and keikaku, but ultimately knew he probably deserved his death at the end.
unless you thought he was a moral person then you're represented by Misa
I think what he did was generally good, I mean he certainly could have done a hell of a lot worse things with the power he had. The power to kill anybody you want doesn't really lend itself to grand acts of benevolence most of the time...
That said, he knew the stakes he was playing for, and accepted that when he started, so I think his death was also perfectly justified as a consequence for failure.