So pleased to see the Leuchtturm 1917 dotted grid at the top of this list. It's been my go-to notebook for the last few years. It comes with some nice stickers for labeling so that you can find past notebooks on the shelf. Lots of colors are easily available on Amazon.
I wrap my latest notebook in a Coal Creek leather cover to look all fancy (and hold my phone and pen). https://www.coalcreekleather.com/collections/a5