So much to say about this Zoo. Not only is it a Zoo, but the Gardens are just as fun to look at. They have a lot of other after-hours events to go to (and not just for the kids either). Check out their web site, then go to the "plan your visit", then go to "Featured Events". They have wine tastings and special tours.
Boo at the Zoo: your kids get to wear their costumes more than once a year. They have a trick-or-treat trail, 3-D spooky movie, hobgoblin express, monster mash dance floor, and the marry-go-round. Tip: Make sure to buy your tickets in advanced. The lines can get very long on popular nights and if you have your tickets, you can walk right in.
Lights before Christmas:
Haven't done this yet, but will be this year.
Memberships: If you go to the zoo a few times a year, check out the membership to the zoo. You will get discounts on all the featured events and you will get free tickets every time you go to the zoo, including free guest passes and free tickets to the Lights before Christmas.