Sans the Skeleton (Undertale)

 Note: The comic sans font is intentional because of the way Sans talks and that Sans' name is based off of said font."

Sans is the brother of Papyrus and a major character in Undertale. He first appears in the forest after the protagonist exits the Ruins. He serves as a supporting character in a Neutral and True Pacifist Route and as the final boss and heroic antagonist in a Genocide Route.

 Why He Rocks

 * 1) Sans is a very cool and laid back character who doesn't worry about any actions being done, believing that it will "all be reset one day".
 * 2) He is very observant, as throughout the game, he reads the protagonist's expressions and can tell when they've already done certain tasks.
 * 3) He has a scientific background, showing that he is possibly very intelligent.
 * 4) He has unique abilities, like the Gaster Blasters, that shoot large beams, and KARMA, which is more effective on the protagonist depending on how many sins they have committed.
 * 5) It is hilarious when he plays the trombone. It is considered a running gag whenever he does.
 * 6) He is so self aware that he know when the game's code suffers bugs and calls the player a "dirty hacker" if they achieve a somewhat impossible ending.
 * 7) He serves as an endearing and helpful protagonist in the Neutral and True Pacifist Route and as an awesome and hard to beat antagonist in the Genocide Route.
 * 8) His protective, brotherly relationship with Papyrus. He will even avenge him if the player killed Papyrus in the Genocide Route.
 * 9) His relationship with the protagonist is cute, mostly in the True Pacifist Route, as he enjoys pranking them and hanging out with them, unless they kill Papyrus.
 * 10) His platonic but heartwarming relationship with Toriel.
 * 11) His jokes are hilariously corny.
 * 12) His lines in the game are hilarious, such as "quick! behind that conveniently-shaped lamp!" And some of his other lines are very heartwarming, such as "you never gained LOVE, but you gained love."
 * 13) He performs at MTT Resort, which hints that he is a talented comedian.
 * 14) He has spawned several internet memes.

Bad Qualities

 * 1) His reason for being lazy can be considered as slightly nihilistic.
 * 2) He has complete disregard for his job and often takes naps at inappropriate times.
 * 3) He annoys his brother with his trombone playing, yet stated in WHR #5, it's hilarious.