Power supply for Raspberry Pi 4 (uses USB type C). If you have an older Raspberry Pi model, you should get a power supply that uses USB type B (scroll down to the end of the page).
Make sure you get the right adapter for your country.
eBay - Power Supply for Raspberry Pi 4 USB-C DC 5V 3.0A US UK EU AU Plug
$7.97
eBay
Amazon.com - Raspberry Pi 4 Power Supply (USB-C) with on/Off Switch (US plug)
Amazon.com
Amazon.es - Power supply for Rspberry Pi 4 5V 3A USB Type C with on and off switch (EU plug)
Amazon.es
Amazon.de - Power supply for Rspberry Pi 4 5V 3A USB Type C with on and off switch (EU plug)
Amazon.de
Amazon.de - Power supply for Rspberry Pi 4 5V 3A USB Type C (UK plug)
Amazon.co.uk
Power supply for Raspberry Pi 2, 3 or 3B+. USB type B.
eBay - Power Supply for Raspberry Pi 2, 3, 3B+ DC 5V 3A/5V 2.5A US UK EU AU Plug
$2.46
eBay
Amazon.com - CanaKit Raspberry Pi Micro USB Power Supply
Amazon.com
Amazon.co.uk - Official Raspberry Pi 3 Power Adapter UK/EU 5V 2.5A
Amazon.co.uk
Amazon.de - Power Adapter EU 5V 2.5A - Suitable for Raspberry Pi 3
Amazon.de
Amazon.es - Official Raspberry Pi 3 Power Adapter UK/EU 5V 2.5A
Amazon.es