Avoid Mornings
The elderly woman who works the cash register some mornings is extremely slow. The line will stretch halfway to the back of the store. Once you reach the register, prepare for the slowest transaction ever. I once stood in line for over half an hour (out of morbid curiosity) to buy a soda and a pack of cigarettes. It is faster to walk up the street to the Dollar General if you can.
If the older lady isn't working, the other people who work there are all nice and very quick.