The cane, every time!
My wife used to use her hairbrush to spank me, but that was too noisy when our kids were getting older. We already had a rattan cane which was kept for special occasions when I had to be given stricter discipline, so that became her implement of choice. It makes a delicious whisper and a relatively quiet "Whap!", much quieter than the hairbrush but more stingy-burny.
A good caning works very well for us. When I have to be disciplined I prefer its clean bite on my bare bottom, so if I am given the choice (as happens sometimes!) I always choose to be caned.
My wife's favourite cane (she has three) is the thin whippy rattan one with the crook handle, which I made for her myself. My bottom has got to know it VERY well!