I've been using Ctrl-[ instead of Esc for so long that I forget that a lot of people don't know about it. This may not be convenient on non-English keyboard layouts.
small fun fact:
I switched to this when the escape key was taken from me (thanks again NOT apple)
After switching to a newer MacBook that has the escape key I did not start using that again, but stuck to the Ctrl-[ as it just works.
mvanbaak|2 years ago
metaltyphoon|2 years ago