All zones are good really. Some are better than others for specific things, but its not like one zone has the corner on any one material. For example there is one place in one zone where I can find a lot of Nirnroot in a concentrated area, but that does not mean it is the best zone for Nirnroot. Auridon is not great for Ancestor Silk, but does well for metal, but you can find Ancestor Silk there.

So, tired of Deeshan, pick another zone and go farming.

I farm in craglorn since you can also find nirntrait mats there