Just about anything electronic. At about 10 I built my first radio it was a cat's whisker and copper coil around a toilet paper roll. I got the ear bud from a neighbor who bought a three transistor radio and promptly dropped it in the lavatory while he was shaving. I also build wooden tall ships. Two to three feet long and 18 to 24 inches tall (but they take years to finish).
I like combat strategy type games like Eastern Front, Invasion Orion, War in Russia, Combat Leader etc.