MarkoH01: I loved every game mentioned above especially Deponia. Badly written? I could not disagree any more. Unfortunately obviously most non German people need to have a sympathetic protagonist to enjoy the game. It's kind of funny - Deponia has been a big hit in Germany while people outside Germany - especially americans - really disliked it. Story based games like point and click adventures will always be problematic to judge since different people have different tastes.
I don't think it has anything to do with nationality. I enjoyed the first Deponia game very much, but in the second game Rufus really became an annoying self-centered jerk. And even the much better German voice-acting (compared to the English one) didn't change that.
Strange enough I really enjoyed Randal's Monday though, another game which a lot of people hated, because of the non-sympathetic main character.