a classy watch, a new wallet, something that accessorises him a bit depending on what he likes to wear - new hat/scarf/belt/shirt/tie
If he likes music, get him a C.D or create one / get concert tickets for the two of you / take him on a night out to see a band at the local pub. All boys like new gadgets, so maybe a video game console with the latest video game or a kindle. If he enjoys art or theatre take him to a show he might enjoy.
However, it really does depend. I don't know how much you are willing to spend, what kinds of things he likes/interests he has, the kind of guy he is or if you want the gift to be casual or romantic.