A few more games that can be used with the Hori pad, taken from:
http://www.nintendospin.com/article975.html
Resident Evil 4
Surprisingly, one of the GameCube's best titles is playable with the Hori pad. RE4 uses the c-stick for camera adjustments and the sniper rifle. The latter is definitely important, but it's only necessary in certain sequences, so the game can be played in huge chunks with the Hori pad. In fact, the d-pad and the button layout are actually well-fitted to this action game. Aiming was still easy, though not as precise as aiming with the analog stick. The Hori pad can also be used to play the other Resident Evil titles on GCN, with the exception of Resident Evil 0, which requires the c-stick to control your partner. Capcom's Resident Evil franchise is easily the best choice for using the Hori pad.
Metal Gear Solid: The Twin Snakes
This game works surprisingly well with the Hori pad. The game uses the c-stick in certain situations with your back to the wall, but it's not necessary and this game is completely playable with the Hori pad. As a matter of fact, playing Twin Snakes with the Hori pad felt very natural, and Snake's actions were all easily executed and very responsive.
Need for Speed Underground
The Need for Speed game uses the c-stick for looking back. The game can be controlled with the d-pad, and the Hori controller's larger digital pad actually controls the cars very nicely, though again it's not as precise as an analog stick. Still, with the sensitivity with which the analog responds in the game, some may actually prefer to play with the d-pad.
Some other games that can be played with the Hori pad (though with slightly limited functionality) include
Madden and the
Phantasy Star Online games.