Originally Posted By: chaosmagnet
It's harder to give yourself a hot pocket, and twisties are more reliable than clickies. Twisties tend to be shorter (and thus easier to carry). Some people prefer twisties because they feel it's easier to operate them.

Bingo! That's basically my list of reasons, too. The Mini Maglite and Solitaire are also twisties.

However, to be fair, the very common coin cell keychain lights are...well, not exactly clickies, but certainly not twisties, so twisties are not the only reliable game in town. I've had the same Photon II on my keys for over 10 years and the switch has never failed to light up yet. I forget if the Photon II is waterproof, but all that dirt, lint, dead skin cells and sweat hasn't bothered its switch yet.