My family and I just returned from nine days in Buenos Aires and had a very good experience with significant help from this forum. As a first-time visitor to BA, and to Argentina, wanted to share some lessons and dispel a lot of the myths I read about on this forum and others. For context, I traveled with my wife and our 7yo and 3yo. None of us speak Spanish and I was the only one who had previously visited a developing country.
-Warnings about safety are overblown. Yes, crime is certainly a big issue even in the nicest parts of BA. But if you've lived in an urban environment in the US or Europe, a lot of traveling around the city is commonsense. Dress like a local, don't flash expensive jewelry, electronics, or cash, and don't unfold a big map on the streets. Heck, it sounds like if you skip Av. Florida altogether, you'll avoid many of the scams. From what we saw of it, that was one of the least attractive parts of the city anyway so you won't miss much.
-Radio cabs (remise) are very easy to hail on the street or have a restaurant or hotel call them for you. At current exchange rates, we found it hard to go anywhere for more than the equivalent of US$6.
-Bring USD and change it on the blue market, which is a lot easier to do even from us non-Spanish-speaking gringos than we ever expected, or use a wire transfer service like Xoom.com. The additional AR$2-3 you get per US$1 will go a long way during the trip.
-The modern art in BA is fantastic. MALBA is to open until 830p or later every night and is a pretty quick jump over Palermo Soho for dinner -- even compared to DC and NY, it was very exciting to have a pre-dinner date at a hopping museum filled with interesting art. There are also two relatively new museums in San Telmo, MACBA and MAMBA, with more contemporary and modern art that are worth the trips. The architecture for all of these museums were interesting enough to keep our children occupied.
-It's hard to overstate how wonderful the parks are. We live in DC and spend a lot of time in NY and SF and BA beats them both hands-down in terms of diversity and activities in the parks -- it's a lot like Paris in that way, but with a much more relaxed attitude. This alone made it our kids favorite city to visit!
-While we were disappointed with much of the food, and particularly the pizza, the helado was as great as advertised. Our favorite was Jauja in the 3900 block of Avenida Cervino. It focused on Patagonian ingredients and had really creative flavors. In Recoleta, Cafe Gretha is an excellent spot for breakfast or afternoon cortado (and leche con chocolate for the kids). The staff was extremely attentive and patient with our children and makes excellent, in-house pastries, including medialunas, of course! Also loved Cafe Rivas in San Telmo and Las Pizarras in Palermo. The food at both was superb and prices extremely affordable. They're more date-night than for kids, but far less tourist-y than most of the parillas we walked past.