I knew kawaii before i was learning japanese.When i actually started learning the language i think the first word i learned was genki, It was a long long time ago so i cant remember if its true.
"bakaro/bakayaro" -meaning stupid. or idiot :)
The first word i learned was "kute" (fire, guns fire) in "Last samurai" 2003
I have no idea I think it was maybe like Sayonara. One of my first grade teacher's husband was Japanese so it'd be a bit harder for me to be completely sure about the "first" word. That would've been like in 92 or 93.
chikara - it means power,capability. I liked it so much i ended up using it as my online name in a lot of places. I also have the kanji for it tattooed on my shoulder blade
こんにちは~ Konnichiwa
Liars. I know the first word for everybody was "sushi". ;)
BAKA was my first japanese word to lern it sort of stood out when i watched anime.
The first Japanese word I learned is arigatou (ありがとう). I learned it when I was watching anime.
Konnichiwa (こんにちは)
Either Usagi or Chibi. 
Thanks, Sailor Moon...
Hmmm.. If I remember correctly, it was either Doki Doki or Kokoro, since those 2 appear in every damn song I listened to >.< 
Probably Konichiwa. Baka and kawaii come in close second.