For the purposes of record keeping, here are Sebastien's words in August-September 2007 (at 16-17 months of age).  Just found the sheet where we recorded them. 

As for first words, I think "cat" and "dog" were among the first.  "mama" and "dada" only came months later.  I've starred the "early" words, i.e. words that now we remember to have been his early words.  If only we'd kept better records...

airplane
* ball (ba')
* baloon (ba'oon)
banana (nana)
* bear
bike
* bird
boat
book
bus
bye bye
* car (cah')
* cat (ca')
cheese
cow
dada
* dog (woo woo)
down (dow')
duck
fish
frog
* hat ('at)
horse (shee)
Jenny (nenny)
juice
mama
more (mo')
outside (oufside)
pacifier (bah)
penguin (pimbin)
sheep
shoe
squirrel (squibah)
train
truck
up (upff)
water (wawa)