I like this one:
Amazon.com: SunFounder 4 Channel 5V Relay Shield Module for Arduino UNO 2560 1280 ARM PIC AVR STM32: Computers & Accessories
I was planning on using an Arduino Uno knock-off for my micro, so this board would attach like any other shield. This board will work with pretty much any microcontroller that spits out TTL for control. I believe they will need only 10 mA or less from the logic source per input.