Bombay Grill at 245 Bush River Road in Columbia is EXCELLENT. I have recommended this place a time or two here on chowhound, but this place truly is outstanding and deserves a thread of its own.
For folks who have been around Columbia for a while, Bombay Grill is located next to Chik-fil-A, in the old Golden China building, across from St. Andrews Baptist Church, and situated within the Boozer Shopping Center parking lot area. They are open for lunch and dinner six days a week (closed inexplicably on Tuesdays). They have no beer/wine license due to their proximity to the church across the street, but the owner told me that you are welcome to BYOB.
Now, as for the food, I don't know what to say except that it is far and away the best Indian food that I have had outside of London. Dosas, biryanis, curries, etc. etc. It's all great, and I heartily recommend it. The owner is a sweet young mother and a gracious hostess, which is nice. But the food is the star here.