By boards I assume you mean micro-controller solutions?
I'm partial to AVRs as far as micro-controllers go. But I hear ARMs are a step above.
Some people like Pics. My very first project was on a Pic and I didn't find it as
enjoyable as working on the AVR.
In any case, do you have something a little more specific you need to know?
Generally you just need a micro-controller that has A2D, Serial, and PWM, and
a few GPIO lines. Almost every micro-controller has those so it's kinda a personal
preferences / ease of use thing(for YOU, not what someone else thinks is easy).
I think my preferences when it comes to robotics might be slightly odd... So maybe
I'm not the best to ask. Maybe Admin can point you in a better direction....