What to do, what to do? You have an old arcade game, beaten up and weathered and you'd like to restore this fine piece of your childhood. The great thing is, you have options today you didn't have a decade ago.
Stencils are a great way to keep it classic and original but they can also be a hassle. You need a lot of time and a lot of space. You need time for each layer to dry before adding the next color layer.
Decals are not original but do offer a simple, quick and easy solution for your restoration. The colors will pop and won't fade like paint.
Popular Stencil Sets for Arcade Games: Defender, Moon Patrol, Joust, Make Trax, Robotron & Sinistar all from Williams. Stern had Bezerk, Gyruss and a generic Stern and Taito also did a generic stencil. Gottlieb had Juno First & Mad Planets. Bally/Midway had Pac-Man and Ms Pac-Man and BurgerTime just to name a few.
Which is best? That's up to you. It's a matter of personal taste but a matter of time, energy and expense. Sometimes, the best thing is to do nothing. Leave it worn out and beaten up. I like when the sides of a Pac-Man are rubbed down from years of hands holding on for dear life.