For an excellent market experience don鈥檛 miss the massive Mercado 16 de Julio, which stretches for many blocks along the main thoroughfare and across Plaza 16 de Julio. This shopaholic鈥檚 paradise has absolutely everything, from food and electronics, to vehicles and animals, all at reasonable prices.
You鈥檒l have to fight your way through the crowds, though. (Warning: watch your wallet in both senses of the phrase).