/cg_draw2d (deafult: 1)
Will turn your HUD on and off (0=off, 1=on)

/cg_fov (default: 90)
Will alter your on-screen field of vision. Lower settings are more zoomed in; higher #'s give you a wider view, but can get skewed at anything above.

/cg_zoom fov (default: 22.5)
Will alter your FOV when in "zoom" mode.

/cg_drawFPS (deafult: 0)
Will display your framerate in the upper right of the screen. (0=off, 1=on)

/cg_drawGun (deafult: 0)
Will toggle your gun model on and off the screen. (0=off, 1=on)

/cg_drawTimer (default: 0)
Will display elapsed game time in the upper right of the screen. (0=off, 1=on)

/cg_gibs (default: 1)
This activates the splatter that is so much a part of shooters these days. Setting to "0" can help keep things clean in heavily trafficked games. (0=off, 1=on)

/cg_simpleItems (default: 0)
Will turn all items into 2D sprites. Can help improve performance on slower systems. (0=off, 1=on)

/cg_drawTeamOverlay (default: 0) Will toggle the very useful "team overlay" on your HUD, which will allow you to see the health, armor, and current selected weapon of all your teammates. (0=off, 1=on)

/cg_thirdPerson (0/1; default: 0)
/cg_thirdPersonAngle (0-360; default: 0)
/cg_thirdPersonRange (default: 40)

These three commands will allow you to play with Quake III's "third-person" view. Setting /cg_thirdPerson to 1 will activate the view, and /cg_thirdPersonRange will set how far behind you view your player from. /cg_thirdPersonAngle will rotate the camera around your player; set the angle to 180 and you'll get a good head-on look at your model.