Chiloe, at1950 Howell Mill Road in Atlanta has really good margaritas and a great deal too (for a imited time) - 2 for 1 Margaritias during Happy hour (5pm-7pm). Food is a mix of Latin/Carribean and resonably priced. Limited but good menu, recently opened and new to Atlanta.

Nuevo Laredo Cantina is also a good choice.