I suppose it depends on how you want to use the notebooks, specifically.
If you use fountain pens, brands like Rhodia, Clairefontaine, Tomoe River, Midori and many others come to mind.
If you want a good notebook for using pencils, Ogami has a rock-solid reputation (sorry, couldn't help myself).
If you want fancy, loose stationary paper, you have have a completely different set to choose from.
I thought of you because of your thread and...