Mitsuo Yamaki and Terriermon
I believe Yamaki leaves a very good impression on the first few episodes and is quite menacing. We never see other adults openly acknowledge Digimon, without their kids or someone close getting involved. I was going to go with Takato's teacher just because in the dub she is Kari's voice actor. It was really surprising and as a kid I was waiting to be revealed that she was actually the one and only Kari we all know and guide the kids, but that's just 11 years old me broken dreams. Anyway this is my headcanon and no one can change it. She is Kari in disguise and that's that.
I choose Terriermon because first he is awesome second Asher is going to pick him every time cause he is white with green accents.. come on. We all know that Asher LOVES Terrriermon. So yeah.