Just as I was updating my artwork, I saw the bezel art for Motorfish's cabinet. Although it was actually very simple (mostly just text from the MAME website), its light text on black background gave it a very professional look. I immediately stole the idea for my own cabinet.
The left side of the bezel shows the button layouts for the front end, jukebox, Stella, and Daphne:

In the bottom left is the main MAME control map and the keypad map for Space Wars:

In the bottom right is the shot chart for Golden Tee and instructions for calibrating the lightgun.
Above that, you can see the bottom of the left side, which is simply a list of games and their buttons./p>

Finally, here's a closeup of the MAME control map:

The bezel instructions are just printed on plain paper. I lightly sprayed the back with spray adhesive, making them about as sticky as a Post-It Note.
Here are links to the actual art files: