LogFAQs > #972290435

Asymmetrical because it allows you to hold the controller in the most natural way possible in most games. Symmetrical joysticks only make sense for games that use the D-Pad as the primary input method for movement.

On the other hand, plenty of games these days (especially FPSs and first-person RPGs) put the camera on the right stick, so you'll be spending a lot of time using both sticks simultaneously anyway. And if primary game input is the triggers and you're only using the right buttons for specialized controls, you'll actually be using the right stick way more than the right buttons (and in that sense, it's not that different from games that add separate contextual commands to the D-Pad).