I guess -R (recurse directory) and -l (print filenames containing matches) are two that I use often. The one liner is a bit of a mouthful.

But just for fun:

perl -MFile::Find -ne 'find(& sub { $f = 1; if (/pat/ and $f) { $f = 0
+; print $File::Find::name . "\n" }, "mydir");'
[download]

...or something like that.

-Andrew.