"mommy" was the first, which pleases me to no end. then "eat", "daddy", "bye bye", "meme", "hi", "pop" (for bubbles), and "papa". yesterday he added "thank you".
he also makes nearly every animal noise including a very cute "peep, peep, peep" for baby chicks!
it's very fun to enter into this stage with him. i'm looking forward to watching him learn many more exciting new things!