Check this thread
here. Pretty much every sleep aid has been talked about there.
As far as Benadryl: I find it knocks me out, but I'm groggy as hell the next day.
The best combo I've personally found so far is a Mg/Ca supp, with a high Mg content, combined with a high quality herbal sleep supp (Valarian root, a bunch of other stuff). Seems to work consitantly, with no side effects.