I finished my little moleskine sketchbook the other day...and while I think their branding is a little ridiculous, they hold up far better than any other sketchbook that size. As this is the sketchbook that is most often with me, it tends to get a lot of random notes and doodles instead of thought-out drawings. I really like how it is as an object, which is hard to show on the internet, but hopefully these tiled scans give you the idea.
A large chunk of the book has to do with dinosaurs. Because, you never know when you might have to explain dino--->bird evolution to someone, and describing pelvises is kinda tricky without pictures.