I don't know much about books and publishing groups and stuff, but I do pay attention to producers and labels of bands, actually. Most labels tend to sign similar-sounding artists and usually stick with the same producers and recording studios. To call one my favourite is just picking which label has tastes most similar to my own, or which has a lot of my favourite musicians, much like with animation studios.
I agree about Madhouse, though. They've still made a few decent movies and they still have Hellsing Ultimate, I guess, but they have kind of faded into obscurity the past few years, aside from Kaiji S2. I'll just keep waiting for Ippo S3.
Our tastes seem pretty similar other than your distaste for Kyoani, though. I guess we can still be pals. Put 'er there.