Here you will find most usefull (in my opinion) design patterns implemented in JavaScript. Enjoy! :)

• Constructor functions that can be used to instantiate new objects
• Factory factory simply generates an instance for client without exposing any instantiation logic to the client
• Prototype In this, we use a sort of a “skeleton” of an existing object to create or instantiate new objects.
• Singelton pattern where only one instance of a class can exist.
• Abstract Factory factory that groups the individual but related/dependent factories together without specifying their concrete classes
• Builder separate the construction from its representation. Useful when there are a lot of steps involved in creation of an object.

• Adapter lets you wrap an otherwise incompatible object in an adapter to make it compatible with another class.
• Bridge decouple an abstraction of object from its implementation so that the two can vary independently
• Composite composes objects into tree-like structures to represent whole-part hierarchies
• Decorator lets you dynamically change the behavior of an object at run time by wrapping them in an object of a decorator class.
• Facade provides a simplified interface to a complex subsystem. (jquery)
• Flyweight minimize memory usage or computational expenses by sharing as much as possible with similar objects. (memoization, cache)
• Proxy provides a placeholder for another object to control access, reduce cost, and reduce complexity.

• Chain Of Resp Request enters from one end and keeps going from object to object till it finds the suitable handler. (even propagation)
• Command provide the means to decouple client from receiver. (Reciver, Command, Invoker)
• Iterator way to sequentialy access the elements of an object without exposing the underlying presentation.
• Observer defines a dependency between objects so that whenever an object changes its state, all its dependents are notified. (Pub/Sub, Observables)
• Visitor let's you add further operations to objects without having to modify them.
• Mediator control the interaction between two objects (chatroom, users)
• Memento capturing and storing the current state of an object in a manner that it can be restored later on in a smooth manner. (edit ,save, restore)
• State lets you change the behavior of a class when the state changes. (waiting for payment ,procesing, shipping)