starter or something else?

I got off work today and when I turned the key the engine wouldn't crank just one click, non of the lights dimmed.

I asked my buddy to turn the key while I tapped the starter and the car fired right up.

When I got home the car started up fine without tapping the starter.

should I replace my starter? or is something else wrong?

2004 TL - 111000km

EDIT: sorry thought I posted this in the Problems & Fixes.