After Ma ma and Da da, Saben's first two words were cracker & zoo. Cracker is by far his favorite word & one he also uses for rocks, or other objects that look like fun to pick up and are lying on the ground such as woodchips. I guess "Rock" and "Cracker" sound similar... except rock is actually easier to say. And you guessed it, Saben LOVES to eat crackers. He started with "Caca" but has been practicing his annunciation enough that you can now hear both r's quite clearly.
Zoo came about because we have this Peek-a-boo book where they replace "boo" with words that rhyme like zoo, moo, choo choo. It is one of his favorite books. Zoo actually started as "Znn" but the z sound was so good and he used at the appropriate instance, so we gave him credit for it. He does pretty well with Moo & Boo, but often switches them. Zoo is definitely his favorite.
He doesn't say many other words yet. As I mentioned previously, "This" is another favorite. Other than that, he says "da" for dog & "buh" for bird. I think that's it. When he sees candles, he blows. When he sees flowers he sniffs. He is a communication mastermind.