I bought a sketchbook at the National Gallery of Art from a brand that I had never even heard of. It's a small landscape sketchbook called a "flexisketch", and I love it. 
The paper quality is just what I need for jotting notes and making sketches and the size is perfect for me.
I find that I do a lot of character sketches or small notes to myself, but I also like taping, stapling, and sticking things onto the page. It helps keep me interested in what I'm working on and hopefully make it more entertaining for whoever happens upon my little book.