I have just learned that Microsoft has just released a site in which developers can search examples posted by other users. Which I think can be pretty helpful if your still starting out on a certain language or a feature. But you might be thinking, what about CodePlex? Well, this is entirely different from codeplex, although you can see some bundle of samples in codeplex (SQL Server samples, to name a few), I think codeplex is a place to start a new OpenSource project in which you let your friends or all people participate in. The new Code Gallery was built mainly to have a place in which people can share their sample codes to others.
So far, here are my favorite samples that I found to be useful:
Main Page: MSDN Code Gallery