Shane just turned 25 last week, and he recieved a camping air mattress, a cooler, a trailer hitch for the Jeep (which just got stolen), a $100 gift card to Home Depot, and I bought him a recliner/rocker. He was thrilled with all of them!
If your friend has a house or likes to do home improvements, I would suggest a gift card to Home Depot. I did buy Shane an RC car last year, as was mentioned, and he LOVED that! Another really good one would be a gift certificate to a racing place....you know, those places where there is racing in those italian go carts? Boys and their toys...what can I tell you?