For my dollar, this is the best notebook/organizer on the market. Luckily, there is a version available for types of budgets and tastes. This system was originally developed by Rollabind. They produce their own version of the product and also license it to a few other companies. Levenger sells upscale versions in fine leather in 3 sizes: Letter size, Junior, and Mini.
What makes it so useful? First, The pages slip on and off a series of rings. These rings are as big or as small as you need. The notebooks can fold over flat and are easy to fit almost anywhere. Punches allow you to use your own paper, even ringed notebook paper with a Rollabind-style binder. The rings are solid, with a small lip around the circumference. The paper, with its small anchor-shaped perforations, slip over the rings.
The Levenger product is upscale, but they also sell plastic covers to use with the system. Staples sells a faux leather (I've only seen photos on their Website, so I don't know how they looks and feel) and a clothbound version (search for "rolla notebook" on their Website). The clothbound version, for only about $10 (leather is $12), is a good deal. The notebooks have a nice, traditional look to them in two-tone bindings. They include a few extras, like a ruler, page protector and organizer. Levenger, who sells a $100 version of this notebook, ought to throw in a few useful accessories. The ruler is particularly useful, as it can also act as a bookmark. Rollabind sells only plastic covered notebooks. These are excellent for school and come in several colors. I prefer the corporate black and gray. These plastic covers are also good for inexpensive, archival storage of a project.
Incidentally, there is a similar product from Europe (Atoma) with a US distributor (Myndology). Atoma has a wide selection of attractive notebook styles, but they are not compatible with the Rollabind system, so you wouldn't be able to mix and match, but it does offer another similarly-priced alternative.
I'm very pleased with the Rollabind/Circa system, especially since the product is available to fit every budget. Highly recommended.