A button is a button, and a switch is a switch, but these translucent arcade buttons are in a class of their own. Particularly because they have LEDs built right in! That's right, you'll be button-mashing amidst a wash of beautiful light with these lil' guys. They're the same size as common miniature arcade controls, and require a 30mm diameter hole for mounting. Thus they are sometimes referred to as 30mm diameter.
Arcade Synth Controller
Arcade Button with LED - 30mm Translucent Clear : ID 3491 : $2.50 : Adafruit Industries, Unique & fun DIY electronics and kits
Arcade Button - 30mm Translucent Blue : ID 476 : $5.95 : Adafruit Industries, Unique & fun DIY electronics and kits
Arcade Button - 30mm Translucent Pink : ID 472 : $5.95 : Adafruit Industries, Unique & fun DIY electronics and kits
Simple Arcade Button Ideas for Your Projects : 7 Steps (with Pictures) - Instructables
Sanwa OBSC 30mm Translucent Pushbutton Red - Focus Attack
EG Starts 5X 30mm Arcade LED Lights Push Button Built-in Switch 5V Illuminated Buttons for Arcade Machine Games DIY Kit Parts Jamma Mame Raspberry Pi 1 2 3 ( Each Color of 1 Piece ) & 5 Colour : Video Games
Arcade Button with LED - 30mm Translucent Clear : ID 3491 : $2.50 : Adafruit Industries, Unique & fun DIY electronics and kits
Mini LED Arcade Button - 24mm Translucent Blue
Arcade Button with LED - 30mm Translucent Clear
Arcade Button with LED - 30mm Translucent Green
Arcade Button - 30mm Translucent Clear (Adafruit 471)
Simple Arcade Button Ideas for Your Projects : 7 Steps (with Pictures) - Instructables