Design Pattterns in C#

i  would like to know about the design patterns commonly used in c# application.. Some real time examples would be helpful.

I have not heard of a commonly used pattern in a "C# application" that may not be used elsewhere. Btw, what is a "C# application"? Is that a Windows Form .exe program? A web service? An ASP.NET web application? Windows Service? Class library components?

Applying Design patterns requires influence on what is being developed at the moment. Without knowing what the end goal is, deciding which design pattern is anybody's guess. One needs to know what kind of animal to hunt down before picking a weapon. Using an elephant gun on a mosquito is not effective. Also what one developer uses frequently in his design context may not seem common to your own project/business environment.

if you new to Design patterns and wanting a general laundary list, Head First Design Patterns is a good book to get started with. A more specific title would be Design Patterns in C#, which should give you more run-away code to get practical immediately.

Again, it is important to know your current situation and what you are trying to develop for. Only then can you start to consider what design patterns are suitable for such scenarios. Be specific and descriptive.

if all you need are examples on how the common design patterns can be applied using C#, take a look at http://www.dofactory.com/Patterns/Patterns.aspx

I agree that dofactory.com provides some good articles on GOF patterns. However in this post, I would like to introduce one very useful pattern which are used in frameworks, Dependency Injection pattern. martin fowler article describes the pattern in more detail. In a nutshell, using this pattern will let you design a loosely coupled system, or rather a pluggable system. People from Microsoft's patterns and practices has used this pattern extensively in developing Enterprise libary. There are also some DI containers out there that will help to get people started. You can find one of those DI containers, Windsor Container in castle project.