Mario Kart DS

Mario Kart DS is a racing game featuring numerous Mario characters, as well as R.O.B., who hails from two old NES games, Gyromite and Stack-Up. The players not only have to race, but can also use items to attack each other.

Super Smash Bros. series
The Mario Circuit track appears as a stage in SSBB, one of the karts appears as a trophy in SSBM, and Bowser's dash in SSBM utilizes a motor, presumably from his kart. In addition, the aformentioned Mario Circuit stage contains Shy Guys as a hazard, presumably a reference to fact that Shy Guys can be used as racers in multiplayer if a player does not own Mario Kart DS.