Finding original and quality cocktails in Argentina is like trying to find fresh produce in a Walmart - it might be there, but it won't be a diverse range and it won't be good.
Certain countries are known for signature cocktails. For instance, Mexico has the margarita and Peru has the pisco sour. In Argentina, you are likely to find the typical run-of-the-mill selections - whiskey and cokes, bad frozen margaritas, rum and cokes, and vodka sodas.
However, Argentina is known for a few unique concoctions which I sampled. One that stood out is the Gancia Batido. The other, which might be the most famous, is the Fernet Cola.
4 oz Gancia Americano liqueur
1 lemon, juiced (lemon is traditional, or instead try a lime)
1 tablespoon simple syrup or white sugar
Shake and serve over ice in a Collins glass
1/2 measure Fernet Branca
1/2 measure Coke
Stir and serve over ice
These are both the only truly Argentine cocktails I could find. I really enjoyed the bittersweet taste of the Gancia Batido. If you like Campari drinks, or drinks heavy on the bitter/sour, you'll love it.
I had tried a Fernet Cola in the US years ago, and I hated it. Upon drinking it again in a tango club, I was pleasantly surprised at how much I didn't hate it. Be warned - Fernet is very herbal, aromatic, syrupy and strong. It looks like Jagermeister but tastes more like the Czech liqueur Becherovka.
However, we also ventured to a few craft cocktail joints in Buenos Aires. The city is experiencing a trend of speakeasy-style bars. In the hip areas of BA, such as the Palermo neighborhood, there seems to be a "speakeasy" on every other block.
We visited Verne Club and Victoria Brown in Palermo. At each establishment, the decor and setting were meticulous. Both had loads of copper fixtures, leather furniture, dark woods, and low lighting. Verne was a little more traditional; Victoria Brown was styled a little more "steampunk". Their menus were full of avant-garde drinks with creative twists using atypical ingredients. We were excited to try these two places. Unfortunately, for all their creativity, they need to refocus on their taste. Each of the cocktails had an attribute that impressed me, but their comprehensive taste was mediocre.
One of the most remarkable things I've seen in cocktail-ery is the smoky old fashioned at Verne Club. The bar has a unique culinary machine that creates smoke and infuses it into drinks. Verne uses dried herbs instead of charcoal, and pipes it into the glass after the cocktail is made. The barman quickly slaps a lid on the glass to capture the smoke, and removes it upon presentation to enjoy the cocktail in its smoky glory. The smoke infusion gave the drink such a singular, but not an overpowering, flavor. However, the fact that they made this expensive concoction with Jim Beam could not be overlooked. This is just one example of why bartenders should focus on quality over kitsch in their drinks. Many of the other cocktails in BA followed suit; the creative effect was overshadowed by an incomplete taste.