In the past few months, my robot's been powered by an Arduino, a stock ATMega328P in I2C, and a TI SN754410. However, today, through a soldering mistake (somehow shorted 7.4v VBATT to Vcc), the Arduino's 5v regulator died, and with it the motor controller. As such, I'm looking to get a new motor controller or motor driver, hopefully one that is easy to use, because the recent series of board failures is really annoying me. I am using a pair of Pololu gearmotors, peak draw < 2A.
As for the Arduino, I had earlier ordered an Arduino Mega through ebay for $27.50, so when that arrives I'll hopefully use that. In the meanwhile, the spare ATMega328P's I have will stand in.