Not sure if you want to hear this, but one of the best things is simply to give him some good sex. Let him relax while you do all the work. And if you know your man, you'll know what he likes.
If that sounds offensive, my apologies, but that's the honest truth. Depending on how much money you have, you can always get him that little electronic gadget he's been wanting (e.g., iPod Touch, iPad, etc.).