What is your favorite? And how much do you eat?
Mine is valhrona - available at Trader Joe. I would like to probably eat a bar a day. But I eat about 1/4 to about 1/3 of a bar.
Godiva Masterpieces from Costco - individually wrapped - easier portion control.
I truly love Baci’s dark chocolate. They’re not that commonly available.
Endangered Species 72% sea salt almonds is my latest fave. 
Endangered Species tart raspberry is my favorite. Most of what I’ve tried of that brand is delicious! I’m currently trying to avoid chocolate (other health reasons), though I might have had to exert significant self control not to eat an entire pint of chocolate peanut butter ice cream last night…
Valhrona. Each winter I get a 3kg bag of Valrhona Guanaja Les Feves (70% dark wafers intended for cooking) from chocosphere.com, and usually eat about 7 or 8 wafers—a little less than 30g/10g carb. Until they run out. Then I revert to occasional grocery store dark chocolate. Of those, Scharffenberger continues to be about the best I’ve found, although it did decline some after it was bought by Hershey those many years ago.
I am OBSESSED with LINDOR dark chocolate truffles. they come in a bag, individually wrapped. they consistently bring me up between 20-30 points within half an hour, but I get the full effect in about 45 minutes. I only use these for moderate lows (50s) bc they are not as fast acting as other types of tx.
but they are super delicious and very satisfying and just the right size/portion to do their job as well as enjoy without feeling the need to have more than necessary.
(only problem: cannot carry them in your bag or they melt and get all sticky everywhere; must refrigerate them and then take them out once you feel like you are going low, bc they taste best when they are ALMOST at room temp.)
