The sense of insecurity in Buenos Aires changes from time to time. The normal precautions you would take in any city you don't know, also apply to Buenos Aires. Walking around most of Buenos Aires during the day is usually safe, though it is not recommended in Boca outside of Caminito. If you want to take a taxi, get your hotel to call for one. If you have to stop one in the street make sure it's a "radio taxi". Radio Taxi Blue and Radio Taxi Premium are long established companies.
There is a wide choice of hotels in the city. I have stayed at the small and traditional Meliá Recoleta Plaza in Recoleta and at Hotel Madero in Puerto Madero which is a larger "design" hotel. I enjoyed my stay in both.
Casa Rosada in Plaza de Mayo |
Climbing in Puerto Madero |