There's still time for December fun, but it depends on how much you want to spend.
For a big outing, see the Rockettes at Radio City, though seats are hard to find now. The show could run you between $250-$500 a ticket.
Closer to home, the Bergen County Zoo offers a walk-through holiday lights display and an ice skating rink for $20 for adults and $10 for kids ages 3-17, but doing it all adds up.
Polar Express train rides are popular. Whippany is sold out, and Flemington has limited seats left for $45 adults and $40 for kids.
Watch out for the New Hope Polar Express ride across the border in Pennsylvania. On busy days, tickets cost $100 for kids and adults, even $20 for infants. A family of five would pay at least $400, and there's a fee if you cancel.