I would like to recommend going to Mar del Plata City, 260 miles from Buenos Aires City. You will find a combination of beauty and charm of its natural resources (vast sandy beaches ideal to enjoy summer walks) with the infrastructure and services. Mar del Plata has everything, and even in winter you can enjoy its nightlife, its pubs, discos, sea museums and the famous Casino. I travelled with the services of Kangoo Tours
If your ready to party until 7am and go to crowded beaches the next day with all Argentinians, hit up Mar Del Plata.
As a city, Mar del Plata is interesting and a lot of fun. As a beach destination, it's a little too densely populated for my tastes. I did enjoy surfing here and the waves are nice, but I could do without the intense urbanization along the coast. I'm more of quiet beach town kind of guy...