If you are overclocking, yes the 3570K is a very good choice. (Newegg: http://www.newegg.com/Product/Product.aspx?Item=N82E16819116504)
But if you are just looking for a cheap good performing processor, the i5-3350P is a good option for about $40-30 less (Newegg: http://www.newegg.com/Product/Product.aspx?Item=N82E16819116782) Same family, same microarchitecture and same amount of cores, the only difference is that it is 300MHz slower (300MHz is hardly relevant these days with quadcores and octacores) and it is not overclockable, and does not have Intel's bad intel graphics. If you are buying the 3570K make sure to buy a good cooler so you can overclock it if you want.
Matsu