Odseven Mini LED Arcade Button - 24mm Translucent Blue Wholesale
The buttons screw in place, so you can use with up to ~15mm thick material, and will cover up if the hole if it isn't perfectly round and clean. The action is smooth, without a strong click, yet you can definitely feel when the button is pressed. A tiny micro-switch is pre-installed, with gold plated contacts.
Even unlit, they look fantastic: all of the colors have a crystal translucent glossy look. As noted they have two surface mount LEDs with resistors built in, buried in the button body. Next to the switch contacts are two additional contacts for powering/controlling the LEDs. The two LEDs are connected in parallel with ~1K resistors each, so you can power the LED from a microcontroller pin or direct from 5V (say USB) with 10mA draw. You can go down to 3.3V power, only 2mA per button, but they'll be dimmer.
Supply Voltage: 5V @ 10mA