Retail stores, usually grocery stores, are a totally different kettle of fish. I will be polite, but a pretty audible "Excuse Me" with a facial expression where I am trying to say "You are blocking the aisle, and I would like to get through." It usually works. I would like to think that people aren't intentionally trying to be rude. It is inadvertent, and they move pretty quickly.
The annoying part is when you meet up with them in another aisle, and they are doing the same thing.
The annoying part is when you meet up with them in another aisle, and they are doing the same thing.