The Traveler's Notebook has been my primary notebook for over five years now. It was originally released by the Japanese stationary company Midori but proved so popular it has become a separate company. For example I use the process described here to keep three notebooks within the covers on my traveler's notebook. I have one dot-grid notebook for planning, one plain notebook as my journal, and one heavier paper notebook for sketching and Copic markers. I love my A5 Falcon Traveler's Notebook (€64), which wasn't cheap, took ages to ship (it's handmade), but is a work of art.