I guess I'd go with τ cause torque changes, while pi doesn't. I like change.

1

π because it is more distinct from the latin letter T and because pies are tasty

TT (pronounced titty)

Tau, my beloved

Pi.

Hmmmm.... Pie... drool

π

ππ

Pi

mew?

Tau

yummy pie

π

τ 'cos it's ~2π. twice the fun.

yes