My daughters first word was baba. And then after that point her second word she learned was dadda and that word haunted me until she hit about a year old. It took her forever before she started saying mama (partially out of just pure stuborness I'm assuming lol). Now she's 3 yrs old and can say anything from I'm hungry to can I go outside or she / he hit me. Her vocabulary has definitely came along ways from when she was 6 months old but to me I think the most important words I could ever hear come out of her mouth are the words I love you.