If your not doing repairs on a budget, or you don't exactly know what it is that you need, I would suggest you go to Autozone because 9 times out of 10 they will have the part your looking for, as well as being more than able to tell you whats wrong with your car or if you even need a new part. On the other had if your working on a budget, or have repaired cars before and know the exact part that you need, I would suggest going to your local auto parts store.
Only bought something there once but the service and store layout was just fine, nothing to complain about.