See the question and my original answer on StackOverflow

You should use the out-of-the-box standard WebBrowser Control that ships with WPF (there is another one for Winforms apps). It has all the basic events directly supported.

Should you miss some Winforms feature like IsWebBrowserContextMenuEnabled or ScriptErrorsSuppressed, I suggest you refer to my answer in this question on SO: How to deactivate "right click" on WPF Webbrowser Control?

You only need interop in these special cases or if you need to get ahold on the native underlying IE's Document Object Model (DOM), interfaces like IHTMLDocument2, etc.