Personally, I would go with ritalin.
Ive had virtually every ADD med scripted to me as an adolescent, cylert, immediate release dexedrine, ritalin, adderal, even wellbutrin.
I prefer cocaine over amphetamine, even though i dont like stimulants in general. This is why i would choose ritalin, because it might not as effective as dexedrine for ADD, but at least you can eat and sleep on ritalin. Not to say i didnt take large doses of dexedrine and experienced a nice buzz, but for some reason i liked ritalin. Its even decent IVed....
But the answer for most people: immediate release dextroamphetamine, generic "dextrostat" works very well