Buffy the Vampire Slayer and Angle both have several BDSM references. It wasn't treated as good are bad, just something some poeple do.

Some examples off the top of my head:
Faith made numerous references to her kinky sex, and was appearently a switch.
At one point Spike shows Buffy a pair of handcuffs and asks her "Do you trust me?"
In a very funny scene, Angle goes to a guy for information, who's wall in covered with paddles. The guy, misunderstanding Angle reason for visiting him, starts to explain that he doesn't spank men. He says something like "I'm sure you have a very nice buttocks, but that just isn't my thing."