I like LED's for their efficiency, but whether or not they are cost effective will depend on how long they last, taking into consideration the energy consumed compared to incandescent and fluorescent bulbs.Or whether LEO's . . . er, I mean LED's are good or bad!
Incandescent is still my favorite for aesthetic considerations. After all, our main source of light is incandescent - the sun! If you want to make sure the new drapes go well with the gun safe, you need to see them in sunlight.
Woody