Formal:
* C'est avec plaisir. (This is with pleasure.) This is the most common and formal way to express pleasure.
* Je suis ravi(e) de vous parler. (I am delighted to speak with you.) This is a more formal and slightly stronger expression.
* J'ai beaucoup apprécié notre conversation. (I enjoyed our conversation very much.) This is a more polite and sophisticated way to express gratitude for the conversation.
Informal:
* Avec plaisir! (With pleasure!) This is a casual and friendly way to express agreement.
* C'était cool de discuter avec toi. (It was cool to chat with you.) This is a very informal and relaxed way to say "pleasure to talk."
* J'ai bien aimé parler avec toi. (I enjoyed talking with you.) This is a more personal and friendly way to express your enjoyment of the conversation.
Important Note: The choice of expression depends on the context and your relationship with the person you are talking to. For example, you would use a more formal expression when talking to a client or a superior, but you could use a more informal expression when talking to a friend or family member.