Light (aka Kira)
In the AngelKiry version, Light's reason for using the Death Note is to spread his pain onto others.
In the TeamDattebayo version, Light's main desire is to eliminate the lesser worthy anime of the world, so he can rule at the top.
In 1KidsEntertainment's version, the author tries to stay as true to the show as possible in order to make sure certain plot points are not too much of a stretch. To this end, Light's motivation in the Abridged is the same as in the original, to eliminate evil and scum from the world. Also, in Episode 1 of the series, Light declares that part of his motivation is to kill "the muffin man", so when he becomes the god of the new world, he will be "full of muffins."
Light is played by 1KidsEntertainment in Episodes 1-5, but changes to work done by xJerry64x in Episode 6.
In the Team Dattebayo version, L is given a stereotypical "Californian surfer dude" accent, and doesn't seem to want to do much investigating, constantly hiring other detectives to do his work, and avoiding questions from the others. One of his catchphrases includes "Rooms to go didn't deliver ANY of my furniture!", referring to the room that L is seen in at the beginning of the series, which contains only a computer, keyboard, mouse, and microphone.
He also seems to be rather uneasy about letting his agents carry phones so he usually has them thrown away. This joke is an obvious reference to the main series in which L constantly tells the investigation members to always put away their phones.
He seems to dislike pretty much everyone on the investigation team, but he seems to hate Matsuda the most out of everyone. One such example of this is when Aizawa grabbed L's arm in anger over Ukita's death and L replies "Get your hands off me or I swear I will kick Matsuda's ass".
His favorite anime is Fruits Basket; a fact Light thinks is rather gay, but L simply retaliates this statement by calling Light gay due to the fact he loves Bubble Gum Princess and his name; Yagami spelled backwards is Iamgay.
Apparently, unlike his anime counterpart, he survives in Team Dattebayo's version as he never dies at Rem's hands and simply doesn't make contact with Light after he is released (this is mostly because the series seems to have been left in a cliffhanger when Light's father threatens to kill Light over the fact he won't go to McDonalds).
The classic comic relief character! Matsuda is used in the original series almost in the same way as the abridged counterpart, at least in 1KidsEntertainment and TeamDattebayo's versions. In TD's version, Matsuda is most commonly found talking with the Chief, which makes some amusing jokes.
"Cool, I feel like Batman with my new utility belt!"
"Matsuda! You can't be Batman! You're a pussy!"
That very same scene in the 1KidsEntertainment version:
"Wow! This is great! I wish I had a belt like this when I was a boy! You see, my mom --"
"Knock it off, Matsuda! No one cares."