Excellent post. I, too, am in the anti-line school of thought. I love to let my hand wander around the page as it pleases and so I usually spring for artist notebooks. I'm a big fan of the Canson Basic Sketchbook series - they come in various sizes. I think the biggest is a 10½" × 13½" and they come with acid0free, heavyweight paper that soaks up the ink of a my pen beautifully. The cover is nice and textured (and waterproof), and the binding is extremely sturdy. Turn to any page in the book and the pages lie flat.

Not a fan of the Moleskine - too small for my taste, even the bigger sizes.