What's your favorite BDSM oriented Toy/Device?

I think the set of velcro cuffs have to come in at No 1 for me. While they don't have quite the same mental impact as rope, they are symbolic and so quick and easy to use. And as soon as they are put on, the sub is completely aware of their position even before they are attached to anything.

I have multiple sets of those. I also have chains to go between them to provide general movement restraint. It has a positive reinforcement of a slave's status when they wear them. Also the weight of the chains is a constant reminder they are there. With 1/4 inch chain, I have 3 link, 6 link, and 9 link chains to make a set. Also each cuff has a snap clip carabiner. The 9 link is for the wrists, 6 link for the ankles and the 3 link when I was either close together but further apart than the carabiners by themselves.

Malkinius

My floggers and rope

Nipple clamps are my favorite

I love nipple clamps on a women. A good pair that can adjust the tension. A lot of women were afraid of them at first, then I show them how to adjust them, and bingo, they always love them after that. You have to ease into things.

Inflatable latex sleep sack, a truly constricting hold

Black iron leg iron shackles with heavy connecting chain and knee spreader bar. Tight fitting belly chain. Gags and masks/hoods. Elbow binders.

Love the clamps, spreaders, forced humiliation with conversation..