Mario

Mario''' is the main protagonist of the Super Mario series and has appeared in every Mario Kart game since Super Mario Kart. He is almost always the 'medium' character, along with Luigi, with all-around stats and karts. Mario usually has a circuit in each game named after him.'''

Characteristics
Mario is most often portrayed in the Mario Kart series to be of average weight, speed and accelleration.

Super Mario Kart
When not controlled by the player, Mario will use invincibility when near the player and attempt to bump into them and make them spin around and lose speed. As stated in the manual, Mario and Luigi are the best choices for beginners because of their medium stats.

Mario Kart 64
In Mario Kart 64, Mario is middleweight and has balanced stats, meaning that he doesn't have any cons or pros.

Mario Kart: Super Circuit
Because of the AI programming in this game, the game will attempt to always make Mario in a certain position when controlled by CPU (eg if the player picks Toad and chooses any race, Mario will usually finish in fifth place).

Mario Kart: Double Dash!!
Mario is by default paired up with Luigi. Mario's signature item is the Fireball and his signature kart is the Red Fire.

Mario Kart DS
Mario has three karts of his own: the B Dasher, the Standard MR and the Shooting Star. Mario's karts are of balanced stats and weight.

Mario Kart Wii
Along with the Standard Karts, Mario also now owns the Standard Bike M and more karts as well.

Mario Kart 7
By the time of Mario Kart 7, Mario now owns (or has owned) 17 karts, counting the Classic Kart that he used from Super Mario Kart to Mario Kart: Super Circuit.

Karts

 * Classic Kart
 * Red Fire
 * Standard MR
 * B Dasher
 * Shooting Star
 * Standard Kart M
 * Classic Dragster
 * Wild Wing
 * Super Blooper
 * Daytripper
 * Sprinter
 * Standard Bike M
 * Mach Bike
 * Sugarscoot
 * Zip Zip
 * Sneakster
 * Dolphin Dasher

Mario Circuit
In every Mario Kart game to date, Mario has had at least one track named after him.

Mario Circuits 1, 2, 3 and 4
These four tracks from Super Mario Kart may be short, but become increasingly hard when one plays them in order.

Mario Raceway
Tracks with names ending with 'Circuit' were replaced with 'Raceway' in all English versions of the game. Mario Raceway is a relatively short track (in Mario Kart 64's terms) at a modest 567m. There is a shortcut which saves heaps of time but needs timing and patience.

Mario Circuit (GBA)
Mario Circuit in Mario Kart: Super Circuit is unique as it has a pit stop near the starting line with a Boost Panel and some Coins. Otherwise, it is just like another circuit-type track.

Mario Circuit (GCN)
This rendition of Mario Circuit has a Chain Chomp at the hill near the tunnel, barking and ramming into nearby karts. There are also Goombas walking across the track at the bumpy section of the track near the finish.

Mario Circuit (DS)
Mario Kart DS's Mario Circuit surrounds Peach's Castle. The enemies present are Goombas, Piranha Plants and Venus Fly Traps which spit out Fireballs.

Mario Circuit (Wii)
Mario Circuit this time round is similiar to Figure 8 Circuit from Mario Kart DS. The awards ceremony takes place here.

Mario Circuit (3DS)
In this Mario Circuit, the players actually can drive in Peach's Castle. Grand Goombas serve as the obstacles in the course.

Mario Circuit (Itadaki Street DS)
Mario Circuit appears in Itadaki Street DS as a playable stage in the form of a board.

Trivia

 * Mario's kart can be unlocked in Nintendogs, along with Peach and Bowser.