What's your favorite secret ingredient?

I realize it's not a very sophisticated way to do this, but post a comment and share your best little cooking secret. Something unique, por favor. Ingredients only. I'll do tools at a later date.

For me: 

Chile con limon - a sort of salt, pepper, smokey shaker you can find in Hispanic grocery stores. It's just a teeny bit hot. Love it on hummus and it's a perfect little extra when I can't figure out what's missing in soup or such. They shake it on fruits and veggies in Mexico, but I'm not fond of that application.

Chili garlic sauce - similar cheater, only more spicy and wet/refrigerated. I go through a lot of this and put it in everything. It's an Asian spice, but I'll throw a spoonful into the spaghetti sauce.