Long Jump

From the Super Mario Wiki

This move is used only in Super Mario 64 and Super Mario 64 DS by all four characters. To use this move, Crouch while in motion and Jump. If the player did this correctly, the character would Jump a long horizontal distance. Many people beat the game without ever learning this move. Mario will regain this move once again in Super Mario Galaxy.

It is possible, yet hard, to do this backwards, an ability that can activate many Glitches.

Jumps
Double Jump | Floaty Jump | Flutter Jump | Fly | Gliding | High Jump | Hop | Long Jump | Power Squat Jump | Somersault | Spin Jump | Spring Jump | SSB Spring Jump | Stomp | Super Dedede Jump | Super Jump | Super Jump Punch | Tornado Jump | Triple Jump | Wall Jump