What Screwdriver To Use For GameCube Controllers

Tri-Point Y0

(Answer Borrowed from HyperKnighttt on Reddit)

The specific screwdriver you should look for is a Tri-Point Y0 screwdriver. Some people mistakenly buy a Tri-Wing screwdriver, but if the bit is small enough, its usually good enough too be used as well. (As you can see in this picture, a small enough Tri-Wing bit, pictured on the top, would easily fit in a Tri-Point screw, pictured on the bottom.)

Tri-Wing vs Tri-Point