I don't like dot-slashing something in the current directory to run it. Prepending a perl is just easier - though that might be different if I was a real touchtypist. So by that token should I do the

#!/bin/sh
eval 'exec perl -wS $0 ${1+"$@"}'
    if 0;
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at the top of my scripts and invoke them all with sh foo? :^)

PS: Since I've replied to half the original question: my editor puts the shebang line in there for me, so I always have one - unless I'm trying something real quick like, which I do just like jeffa (launch perl, paste, Ctrl-D).

Makeshifts last the longest.