Melatonin is wonderfully mild with no residual effects. You kind of just drift off to sleep very gently. It is sublingual, so you just place it in under your tongue until disolved.
Kava Kava was recommended to my by my physician for my GAD, but I chose not to use it, so I cannot speak to its effectiveness.
There is also Valerian Root, but I have not tried that either. I am leery of new herbs/medications, so I stick with what I know to work and not make me wacky in the AM.