I hate chit chat with cashiers or baggers. Really hate it. Well, I don't like chit chat in general really. I think that some people, especially those who seem to end up in cashier jobs, really don't like silence between two people and find it awkward, so they try to fill it with something. But to me it isn't awkward, it's relaxing.
I had the unfortunate experience of working as a bagger in a grocery store, but left after just one month because I couldn't take having to be so fake all the time. If I don't feel like smiling, I'm not going to smile, and if I don't feel like talking, I'm not going to say anything. It's not like I didn't try, but it's just not in my nature to do those things, I am not naturally a chatty or upbeat person. I found having to act friendly more exhausting than bringing in the carts from the parking lot in 100 degree weather. Thankfully I went back to an office job after that, where I don't work with customers and I can sit in silence while I scowl.
I also hate it when you're walking around a store and staff keep asking you if you need help. If I want help, I will ask for it, otherwise leave me alone!! I know that not everyone operates this way, so I understand that they have to do their job and I am not rude to them, but I just wish it was different.