I actually started with @ [1] but changed to ^ for 2 reasons: having to escape for email addresses (although in retrospect maybe it's not such a problem), and the admittedly cheeky ^ being the "up" in "Pushup" :^)
[1] https://github.com/adhocteam/pushup/commit/04aa00bb5401bc93b...
(Or even better against the {{ }} ones requiring 6)
{} is still a common complaint in my circle of programmer friends and everyone has seriously thought even once about switching to an english/american keyboard, but then there's the issue of switching back when writing stuff in french (é by itself almost ruins the idea).
to be fair most special characters are behind AltGr on azerty, soooo...
Personally, I use and love EurKEY [0] as I rarely type in German anyway and rather optimize for coding.