They may sell 'Greek yogurt' (which unlike other yogurts, is strained, (στραγγιστό γιαούρτι, strangistó yioúrti) so thicker and richer than regular yogurts) everywhere, but Greek yogurt in Greece is twice as thick and rich, especially if you find a specialist dairy shop. The marriage of Greek yogurt and Greek honey, with a few walnuts on top, is a marriage made in heaven.
γιαούρτι αγελαδινό (yiaoúrti ageladinó): cow yogurt
γιαούρτι κατσικίσιο (yiaoúrti katsikísio): goat yogurt
γιαούρτι πρόβειο (yiaoúrti próveio): sheep yogurt
σάλτσα γιαουρτιού or σως γιαουρτιού (sáltsa or sos yiourtioú): yogurt sauce.
Image by cyclonebill