Chocolate is not just a food; it is a religion. Specifically, there is the One True Chocolate--dark chocolate (the true faith). But there are dangers awaiting the unwary. Milk chocolate has true chocolate in it, but only in a diluted form that leads innocents away from the true faith (heresy). White chocolate just takes the name of chocolate, but is obviously not really chocolate (paganism). The real danger, though, is carob. It appears to be real chocolate, but upon tasting it, the truth is revealed and the taster's soul is corrupted beyond redemption (satanism).
True Chocolate
Must be both 80%+ cacao AND have great texture AND not be bitter. How is this possible? Anything that dark has to be bitter, right? While hard to find, there are chocolates made from single origin beans, prepared carefully by true chocolate masters, that are very dark, but not bitter. JCOCO's 80% bar is just such as bar (only sold at Whole Foods in the Seattle area as far as I can tell), with a great texture as well. But one step above is Spinnaker's 85% Uganda bar (from a small artisan shop not far from the University of Washington). This is some of the best chocolate in the world. Spinnaker's 85% Columbia bar is another great one, along with their 70% bars (the Uganda and Tanzania beans in particular have an incredible flavor). I'm trying to get them to make an 85% Tanzania... Honorable mention goes to Dolphin's 88% (just a bit too bitter, but has a great texture).
Great Chocolate
There are lots of other great chocolates, though, even if they don't quite reach the level of the chocolates mentioned above. These include flavored bars (that are at least still 70%) and unique styles of chocolate from around the world.
85% Kallari (from indigenous farmers in the Ecuadorian Amazon)
80% Salinae (from Sicily with Mothya salt and a unique "sandy" texture)
75% Vosges Oaxaca (just dark enough, but wonderfully spicy)
75% Republica Del Cacao (Ecuadorian chocolate with a hint of spice inherent in the cacao)
70% Woodblock Salt & Nibs (from Portland, Oregon, a great salty chocolate)
Poco Dolce Peanut Butter Bar (percentage unknown, tastes like a peanut butter cup made by angels)
Poco Dolce Aztec Chile Tiles (percentage unknown, dark spicy chocolate with cinnamon and sea salt, plus pumpkin seeds for an amazing texture)
Real Chocolate
Anything in the 70%+ range is real chocolate, even if it doesn't have truly great flavor and/or texture. These are respectable chocolates, but generally either have some bitterness to them or just don't stand out in any real way.
85% Michel Cluizel Chocolat Grand Amer
85% Bernard Castelain Chocolat Noir Extreme
77% Cacao Sampaka Dark Chocolate
70% Noi Sirius Pure Icelandic Chocolate
70%+ Lindt Dark Chocolate
70% Valhrona Dark Chocolate
70% Chocolove Dark Chocolate
68% Moonstruck Dark Chocolate Chile Variado
Technically Chocolate
Anything that is in the 50% to 65% cacao range. Will do in an emergency, but this is mass-market chocolate for the unenlightened.
Godiva Dark Chocolate
Hershey's Dark Chocolate
Almost any chocolate flavored with fruit, mint, etc.
Chocolate-Flavored Candy
Anything that is less than 50% cacao. Should be illegal to call it chocolate.
All milk chocolates (with the exception of milk flavored dark chocolates).
"Dark" chocolates that are only in the 40-45% range.