I suspect you're talking about all electronic mailing lists, regardless of
the hosting software used.  (LISTSERV is one of many.)

However, I'm not sure how you'd get information on mailing lists hosted by
other software, so I'll concentrate on LISTSERV-based mailing lists for
this answer.

The easiest way is probably to go to
http://www.lsoft.com/lists/listref.html and do some searches.  I did this
and found 35 sites ending in .SE; presumably each hosts multiple mailing
lists.

I hope that this information is useful to you.

-jwgh