It has been some years, but I remember a large commercial lights display near the National Enquirer HQ in Lantana and a private residence just off I-95 in maybe Dania, between Hollywood and Fort Lauderdale.
The Intercoastal is a nice trip as well but you need a boat.
http://www.digitalcity.com/southflor...ghtingdisplays
http://www.southfloridafair.com/
Happy hunting