"It's a pleasure to finally speak with you" or "it was a pleasure talking to you" if the call is over and you are speaking with them at a later time.

It's a pleasure to speak with you. Pleased to meet you

"Nice to meet you" is very common. "It's a pleasure to meet you." "Pleased to meet you." "It's a pleasure to make your acquaintance." (very formal)

It's a pleasure to speak with you. (During the conversation) It was nice talking to you. (At the end of the conversation) Great speaking with you (At the end of the conversation)