I prefer my delimiters to be tall and skinny, just like /. | is tall and skinny, but that leads often to a clash with the special regex character. So, I usually use !, which only gives a problem if you want to use (?!) or (?<!), but they are uncommon enough for ! to be useful. And I often use the balanced delimiters, the four sets of braces ({ } being my favourites). ! I seldom use for matching, only for substitutions, or any of the q* operators, but I prefer / or { } for them.

Only in one liners, vi or IRC, I sometimes use a period when doing substitution, but never in code that's stored in a file.

I don't like to use #, @ or similar characters as delimiters. I know they are popular, but they are too black to my taste, and draw the eye away from the important regex towards the unimportant delimiters.

Abigail