No-brainer.. For me, it's all in the scratch-building of super-details... For aircraft, it's interior ribbing, ammo belts, ring-sights, cables & wiring, engine ignition harnesses and pushrods..
Monogram B-26 radio/navigator compartment
Scratch-built pilot's yoke on the same model:
For Armor it's gun breeches, seating, engines and cooling systems, ammo-stowage, secondary armament, fire-control systems, and that kind of stuff.. One of the things I like to do is with seats and their exposed backs, is to use the little "curlies" from the micro drill to represent the exposed loop-springs in the back of the seat. I'll see if I can get a picture pasted of what I mean.. PhotoBucket's acting up right now and I can't get my "Armor-Interiors" album to open..
I also love kitbashing (Frankensteining) figures, getting the poses I want out of the stuff in several boxes of figures, sometimes taking as many as as three or four different figure sets to get one guy in a pose... That allows me to build the dioramas I do, with the figures made to fit the story, rather than the story fit the available figures...