ΠΑΡΑΚΑΛΌ παρακαλό / pah-rah-kah-LOW / please and also you’re welcome
I got to use this one today! Sure I was ordering gyros in English and just put that at the end of the sentence but I think they appreciated it. I like that they “double-duty” it by making it also work as “you’re welcome.” It’s also used as a way to answer the phone, although I still prefer “go for Dave.”