The Spybots in general were a good intro to the Mindstorms line. It appears that they aren't technically sorted with Mindstorms, but it is closely related.

In my opinion, Technojaw was the best of the Spybots because its claws at the front are actually useful for grabbing objects, whereas other Spybots (including Gigamesh, which had decorative claws) could only push objects around. The claws opened while driving forward, and closed while driving backwards. With some practice, you could get the claws around stuff and drag it around.