>Sugar syrups like golden syrup, gum syrup, maple syrup or honey!
>You can also take soft gummy candies and soak them in hot water for a few hours and then slowly melt them (still in the water!) on the stove on low while stirring. Just let it cool for a while and test the temp first. Adding a lot of water will help prevent it from resolidifying and keep it from burning the pan. Make sure it's enough water to cover all the candies and then some and add more as needed. Stickiest thing I've played with so far.
>I've heard molasses and treacle are crazy sticky too.