Alter Eco Dark Blackout Organic Chocolate, $6.18, from Amazon
With so many companies making great chocolate bars, it's hard to choose just one to recommend. I'm going with Alter Eco first and foremost because I've tried about a half dozen of their bars, from the Dark Blackout Organic Chocolate Bar to the Deep Dark Salted Burnt Caramel Bar and beyond, and they are all amazing.
What sets this company apart is how they make their sweets. Alter Eco products are made with cacao exclusively harvested in Ecuador from sustainable, Fair Trade farms, and all of their chocolate is gluten free, non-GMO, and vegan, and purchases help direct funds to reforestation.