When in doubt - buy him a cordless drill. It does not matter if he already has one. I have a friend who owns 17 and he has yet to complain. As a man, you can never have too many cordless drills. No one knows why.
I sure can't think of anything to add to this list. Being essentially female-less at this point in time, I realize I won't get anything for Christmas, but on the plus side, I won't be receiving any of that stuff that "I look good in".