I am chocolate ignorant. But, I would like to impress my wife. What do you recommend?
There's a pretty broad range out there. I pretty much stick to plain dark chocolate bars, so I don't have a lot of recommendations for milk chocolate, or bars that have fillings or additives. To me, those are more of a snack rather than something to savor.
Most of the bars in that picture are favorites of mine. The Amedei Chuao is by far the best chocolate I've ever had. It has a great acidity that brings out all sorts of fruit notes, with earthy, nutty and coffee notes to back it up. It's about $15 a bar, but worth every penny if you're a connoisseur. If you're into bitter and you want to get adventurous, Domori's "Il 100%" is my favorite 100% cacao bar. It is amazing the complexity you can get off of pure cacao.
Waialua Estate is another one of my favorites. It is 100% American from bean-to-bar: the cacao is grown on Dole's plantation in Hawaii and the bar is made by Guittard. The volcanic soil terroir makes for a distinct flavor profile. The Pralus Cuba may not be the most complex dark chocolate, but it is addictively snackable. It is made from Trinitario beans rather than Criollo. There are three types of cacao beans - Criollo is the top quality, akin to Arabica coffee beans, Forastero is for mass-production and equivalent to Robusto coffee, and Trinitario is a hybrid between the two both literally and in quality of flavor. Pralus tends to go heavier on the roast than other chocolate makers, and that brings out nice peanut butter and espresso flavors in the Trinitario beans, and that makes for a poundable dark chocolate. It also, quite fittingly, makes an excellent pairing with Cuban-style coffee.
If you're not sure how dark you like it, Lindt does a series of chocolate bars starting at 50% and going all the way up to 99%. It makes for a nice flight, especially if you're just starting to get into chocolate. Once you get into it, several manufacturers have single-origin bars so you can get a feel for what chocolate from different countries and regions taste like. I believe Pralus sells some as a sampler of tasting squares so you could do a bunch side-by-side without breaking the bank. The best cacao primarily comes from Venezuela, and the region of Chuao produces the best-of-the-best. I'm also partial to Madagascan chocolate - it has a bright acidity that often comes off as lemonade and/or fresh red raspberries.
You may have to order online to find most of these, but you'll rarely go wrong with these brands:
Domori
Amedei
Pralus
Michel Cluizel
Bonnat
Patric
Amano
Scharffen Berger, Lake Champlain and Lindt may be easier to find and aren't half bad for starters. The Scharffen Berger 70% and the Lake Champlain Sao Thome are excellent starters.