Full Name: Koushiro "Izzy" Izumi
First introduced: Season 1
Power: Crest of Knowledge
Digivolve: Pabumon (baby) -> Motimon (in-training) -> Tentomon (Rookie) -> Kabuterimon (Champion) ->       MegaKabuterimon (Ultimate)

Why I like Izzy: He's a geek.

Izzy is a computer geek and is always carrying around his laptop. He is an only child, which was a side story in the first season. Even if he isn't directly fighting, Izzy helps out with his computer skills. In the future, he's a researcher of the Digiworld.

Joe

Full Name: Joe Kido
First introduced: Season 1
Power: Crest of Reliability
Digivolve: Pitchmon (baby) -> Bukamon (in-training) -> Gomamon (Rookie) -> Ikkakumon (Champion) ->       Zudomon (Ultimate)

Why I like Joe: He's a nerd.

Joe is always worrying and complaining. In the first season, there is a side story about his dad wanting him to be a doctor, but he doesn't really want to. In the second season, he's still studying to be a doctor. In the future, Joe is a Digiworld doctor.

Full Name: Davis Motomiya
First introduced: Season 2
Power: Digi-eggs of Courage and of Friendship
Digivolve: Chibimon (baby) -> DemiVeemon (in-training) -> Veemon (Rookie) -> ExVeemon (Champion)
Digiarmor: Flamedramon (with Digi-egg of Courage), Raidramon (with Digi-egg of Friendship), Magnamon (with       Golden Radiance egg)
DNA Digivolve: Paildramon (DNA digivolve with Stingmon) -> Imperialdramon (Mega Digivolve)

Why I like Davis: Cuz no one on the show does. (He's not as bad as everyone seems to think.)

Davis is the leader of the second season digidestined. He is hot-headed and often rushes into things without thinking. He's really good at soccer and has a crush on Kari. Davis has an older sister that he doesn't get along with. In the future, Davis owns his own noodle cart.

Full Name: Ken Ichijouji
First introduced: Season 2
Power: Crest of Kindness
Digivolve: Leafmon (baby) -> Minomon (in-training) -> Wormmon (Rookie) -> Stingmon (Champion)
DNA Digivolve: Paildramon (DNA digivolve with ExVeemon) -> Imperialdramon (Mega Digivolve)

Why I like Ken: He's just such a cool bishoujen.

Ken started out as the Digimon Emperor, then realized his evil ways and became a good guy. Ken had an older brother who died when he was younger, and that has an impact on the rest of his life. At first he has a hard time fitting in with the other digidestined or being forgiven for his past (either by himself or by others). In the future, Ken ends up marrying Yoli (yuck!) and he is a detective.