Indoor Play Spaces

Branchburg Sports Complex – Branchburg
This 9,000-square-foot mega-complex is chock-full of activities, including laser tag, a PlayMaze, video arcade, and sports such as basketball, baseball, and volleyball.
Drop-in Price: Admission to the PlayMaze and arcade is $10 for the day; batting cage rentals are $60/hour during the winter and $50/hour during the spring/summer. Drop-in soccer is $15; drop-in volleyball and basketball rates will be announced in the spring.
Membership: Annual family membership costs $40 and includes benefits like priority class registration and one complimentary pass for PlayMaze or laser tag. Members also get discounted rates for the following: PlayMaze and arcade – $8 for the day (a $2 savings); batting cage rentals – $50/hour during the winter and $40/hour during the spring/summer (a $10 savings); and drop-in soccer – $10 (a $5 savings). 
Payoff: Depends on what you choose to do. For example, a family membership pays for itself with four hour-long sessions in the batting cage or 20 visits to the PlayMaze and arcade. 

A membership at HudsonPLAY gives you about 40% off regular drop-in rates.

HudsonPLAY – Jersey City
There's something for everyone at this interactive play and fitness center. Tots can play in the soft play area; older kids will love the climbing equipment. Even adults can get a workout on the more advanced jungle gym course.  
Drop-in Price: On weekdays, walk-in children under 5 pay $15 and over 5 pay $30 for a two-hour pass. On weekends, it's $18 for under 5 and $33 for over 5. 
Membership: Annual membership costs $59 and includes discounted admission, two free PLAY passes, and other perks. In addition to the membership fee, members under 5 pay $9 on weekdays and $10.80 on weekends. Members over 5 pay $18 on weekdays and $19.80 on weekends. 
Payoff: For a child under 5, membership pays for itself in 10 weekday visits or nine weekend visits; for a child over 5, membership pays for itself in five weekday or weekend visits.

Kidz Village – Kenilworth and Woodbridge
​Kidz Village is an indoor playground where kids ages 10 and under can climb, play, and explore. While children are working off some energy on the multi-level indoor playground or exploring the themed rooms, parents can keep an eye on them from the comfortable "center of town" area filled with tables, benches, and free WiFi.
Drop-in Price: Children 2 and up pay $11.99 for an all-day pass for, while walkers under the age of 2 pay $9.99. Infants and adults are free.
Membership: Membership plans allow kids to visit Kidz Village as often as they would like with no restrictions. A three-month membership for children 2 and up costs $99, and siblings can be added for $79 each. A six-month membership for ages 2 and up is $179, and $139.99 for each additional sibling. The under-2 set can have a membership for $69 for the three-month plan and $119 for six months.
Stay-at-home moms can opt for the $35 annual pass that allows kids 2 and up to enter for $7.99 and the younger ones for $5.99 on weekdays from 10 a.m. – 2 p.m.
Payoff: For one child age 2 and up, you must visit nine times during the three months to make a membership worth it. That might sound like a lot, but it's a good deal if you want a place you can use as often as you would a playground in the warmer months. When we looked into other similar NJ play spaces, we found you would need to visit at least five times in one month to make a membership worth it. 

Indoor Water Parks

CoCo Key Water Resort – Mt. Laurel
It's always summer inside CoCo Key Water Resort. This 55,000-square-foot water park is perfect for all ages, with attractions that range from thrilling water slides to a wading pool specifically designed for the park's littlest guests. Open year-round, CoCo Key is the perfect indoor destination for those cold winter days. 
Drop-in Price: Day passes cost $29.99 at the door and $24.99 if purchased online prior to your visit.
Membership: An annual membership costs $64.99/person for a full year. A three-month membership can also be purchased for $69.99.
Payoff: Membership pays for itself in three visits.

A membership to Sahara Sam's pays for itself in less than two visits. 

Sahara Sam's Oasis – West Berlin
It may be freezing outside, but it's always 84 degrees at Sahara Sam's Oasis. This indoor water park features rides and attractions that will have your kids swimming, surfing, and sliding the winter blues away.
Drop-in Price: Walk-up price is $36.95; a general admission ticket purchased online prior to your visit is $31.95.
Membership: Annual membership is $54.95/person online or $74.95/person at the door. If you buy four or more, you pay pay $49.95/person online or $69.96 at the door.
Payoff: Membership pays for itself in less than two visits.

Museums

Garden State Discovery Museum – Cherry Hill
Kids ages 10 and under love the Garden State Discovery Museum's 20 giant, kid-powered exhibits, including a working news station and a pint-size supermarket. 
Drop-in Price: $13.95/person
Membership: A family membership costs $114 and includes free admission for two adults and children under 18 for one year. 
Payoff: For a family of four, membership will pay for itself in two visits.

Jersey Shore Children's Museum – Mays Landing
This Jersey Shore Children's Museum offers a hands on-learning experience for young children. The fun and engaging exhibits allow kids to learn through interactive play. Current exhibits include a Post Office, Country Store, Medical Center, and Dino Dig.
Drop-in Price: $8/person including adults
Membership: There are different levels, ranging from a two-person to an eight-person membership. A four-person membership costs $125. There is also an option to add additional adults for just $30/person.
Payoff: For a family of four, membership pays for itself in less than two visits.

Membership at Liberty Science Center gives you unlimited general admission and expedited entry for one year. 

Liberty Science Center – Jersey City
There's plenty for kids of all ages to do at Liberty Science Center. From interactive exhibits to the Infinity Climber, it's packed with stimulating and fun activities. Exhibits are always evolving, so families will find something new every time they visit.
Drop-in Price: Adults cost $31.75, and kids (ages 2–12) cost $25.75.
Membership: A family membership for two adults and up to four children under the age of 18 costs $155. Individual memberships cost $60. Benefits include unlimited free general admission and expedited entry to Liberty Science Center for a full year.
Payoff: Membership pays for itself in less than two visits. For larger families, it's actually cheaper to buy a membership than a daily pass for everyone.

Monmouth Museum – Lincroft
The Monmouth Museum's Becker's Children's Wing is a comfortable, hands-on learning environment for kids ages 7 to 12, where interactive exhibits incorporate fun and education. The Wonderwing is designed for kids ages 6 and under. The little ones will be happy to spend hours exploring a pirate ship, climbing a tree house, and sliding down a whale's tongue.
Drop-in Price: Admission is $8/person. Children under 2 are free.
Membership: A household membership costs $75 and includes free yearly admission for two adults and two children who live in the same household.
Payoff: For a family of four, it takes less than three visits to make membership worth the purchase price.

Montclair Art Museum – Montclair
Introduce children to fine arts at this Montclair neighborhood institution, which boasts an impressive collection of art exhibits as well as programs for families, including the Drop-in Studio art workshops and Park Bench program for little ones. On Thursday nights, kids can create their own masterpieces at the Kids' Creativity Center.
Drop-in Price: $12/adult and free for children under 12. Park Bench has an $18/family fee, while Kids' Creativity Center costs $25.
Membership: A family membership is $75 and includes unlimited free admission plus significant discounts for family and children's programs.
Payoff: For a family with two adults, membership pays for itself in about three visits. Plus, you save more than 60% on family programs. 

Morris Museum – Morristown
The Morris Museum boasts a variety of kid-friendly permanent collections, including Rocks and Minerals, the Dinosaur Den, and Mammals, as well as Mega Model Trains, a perennial favorite that returns every winter. In addition, the museum features ever-changing special exhibitions, making it a great place to visit over and over.
Drop-in Price: Adult tickets are $10/person, while children ages 3–18 cost $7.
Membership: A family membership costs $70. Members enjoy unlimited free general admission for two adults and three children.
Payoff: A family membership is worth the purchase price if you visit just two times during the year.

Newark Museum – Newark
Families will love the Newark Museum's interactive galleries. Kids can explore a one-room school house that dates back to 1784, learn about plate tectonics through hands-on computer animations, and examine the rings of Saturn. The exhibitions are always evolving, so each visit is a new adventure.
Drop-in Price: Adult admission is $15; children's admission is $8.
Membership: Family membership is $80 and includes free admission for two adults plus children ages 17 and under.
Payoff: Membership for a family of four pays for itself in less than two visits.

Aquariums

Adventure Aquarium – Camden
Spend the winter exploring the nearly 200,000 square feet of the Adventure Aquarium, where you'll find sharks, penguins, hippos, sea turtles, and more. There's so much to see that families will enjoy visiting time and again.
Drop-in Price: Tickets for adults and kids ages 13 and up are $28, and tickets for children ages 2–12 are $21.
Membership: The Aquarium offers several membership packages. For families of four and up, the cost is $45 for ages 13 and up and $32 for ages 2–12. Members receive unlimited admission for one year as well as discounts for parking and the gift shop.
Payoff: A family membership is worth it if you plan on visiting more than two times per year. 

Top photo: Climbing area at Hudson Play. Photo courtesy of the venues.