I have a binder similar to the one pictured (perhaps a bit bigger). It has 8 pages with 9 games in each page (trading card sized). So that's 72 games. A shoe box would certainly save space, but the pages can be alphabetized for easy searching. You can also attach a gameslist to the cover of the binder. Some of the binders have slots to insert a cover on the binder.
Trading card size is the best I've found. They seem overly large (length and width), but they are designed to hold the much thinner cards so they expand for the cartridges and hold them snugly.