We don't hate the dutch, it's all banter. Although I have to say, I wouldn't like spending a long time somewhere in an all-dutch environment. I used to think I'd like dutch people better becausee they're more straightforward than belgians, but after spending some time with dutch people I realized that their straightforwardness is just as annoying in its own way as is the belgian (flemish?) reserved attitude.
I personally hate the french. Arrogant assholes that still expect the whole world lays on their feet, should speak their language and act like a rainbow shines out their ass. Also Paris is a shithole and Brussels is its little brother. But the rest of the country is nice to visit if you can ignore its residents.
As far as Luxembourg goes, never visited it. And who has an opinion about Luxembourg or its residents anyway? They're like our mini-Switzerland.
Oh and don't forget the germans. I adore Berlin, don't know about the rest of the country or its inhabitans. You don't want to meet then in large quantities when on holiday in a sunny country. But they're mostly allright, very structured yet a bit weird. They also like beer and it's a bit less shitty than the dutch beer so we can get along.