Depending on their age and if they are interested in robotics then the VEXIQ robot stuff. Biggest kit is this http://www.vexrobotics.com/super-kit.html with motors and sensors you can find smaller sets online. Program in C, a version of Scratch or Python. Built robots are more durable than the Lego versions. Plus there is a competition around them for elementary and middle school students (ages 8-14).
Otherwise the list by sheraz is pretty good.