The history of war, Fighter aircraft, Armor, Tactics, Blowing stuff up.
Pretty much anything to do with military tech. But i love "Fighter Jets" more then anything else. Flying around 600 knots with 130 pounds of ordinance strapped to your plane. Wanted to be a fighter pilot but medical complications ended any chance of doing that. So i do anything else that can even bring me close. Flying civilian or working on WW2 aircraft. And sometimes i occasionally i get to see the transient F15E Strike Eagle, or on very rare occasion. A F-22Raptor when i do its like being a kid again thinking of what it would be like to sit in that seat.
Hats off to those who have that job.