My favorite restaurant in Bluffton [1] is a near-copy of the equally fine Mi Terra Mexican restaurant in Hilton Head [2],
Mi Tierra (101 Mellichamp Center, 843/757-7200, lunch daily 11 a.m.–4 p.m., dinner Mon.–Fri. 4–9 p.m. Sat.–Sun. 4–10 p.m., $3–15). They have very high-quality Tex-Mex style food in a fun atmosphere at great prices.
Another highly-regarded Mexican place in Bluffton is Amigo’s Café Y Cantina (133 Towne Dr., 843/815-8226, Mon.–Sat. 11 a.m.–9 p.m., $8).
Links:
[1] http://www.moon.com/destinations/south-carolina/beaufort-and-the-lowcountry/hilton-head-island/bluffton
[2] http://www.moon.com/destinations/south-carolina/beaufort-and-the-lowcountry/hilton-head-island/food/mexican