Try getting him something he dosen't "need". An example might be something like a remote controll helicopter, almost every guy has little things they want but wouldn't buy for themselvs. Trick might be finding out what they might be.
There are many different things that you can get your husband for Christmas even though he has everything that he needs. You could never go wrong if you got him a gift certificate to Home Depot, guys can never have too many tools.