* 아기 (agi): This is the most common and neutral term for "baby." It's suitable for most situations.
* 애기 (aegi): This is a more informal and cute way to say "baby." It's often used among family and close friends. While similar to *agi*, it's generally considered slightly more endearing.
* 베이비 (bei-bi): This is a loanword from English, "baby," and is used more frequently in informal contexts, often by younger people.
Therefore, 아기 (agi) is a safe and generally appropriate choice in most situations.