Which method do you think is the \"best\".
System.IO.Packaging namespace?
The GZipStream and DeflateStream classes under System.IO.Compression namespace make it pretty easy to zip things up.
UPDATE: Comments correctly state that these classes do not allow you to manipulate a Zip file. However, the J# dlls contain the required functionality in java.util and java.io namespaces. For more details see the Code Project article by dmihailescu which details their use and provides sample code.