Thanks to Justin and Jason for pointing out WatiN. WatiN is inspired by Watir but build for the .NET framework. This means you can write your unit tests using C#, VB or any CLS complaint language. I used WatiN with MbUnit and it worked super great! Let's check out some of the code below:

You need to add reference to MbUnit.Framework and WatiN.Core.

[TestFixture(ApartmentState=ApartmentState.STA)]
    public class TestLoginPage
    {
        [Test]       
        public void TestCanAuthenticatedUserLoginSuccessfully()
        {
            IE ie = new IE("http://localhost:2334/Login.aspx");
            string finalUrl = "http://localhost:2334/HomePage.aspx";
           
            ie.TextField(Find.ById("txtUserName")).TypeText("AzamSharp");
            ie.TextField(Find.ById("txtPassword")).TypeText("mypassword");

            ie.Button("Button1").Click();

            Assert.AreEqual(finalUrl, ie.Url);

            // close the window
            ie.Close();
               
        }
    }

Pretty awesome! The code will open a new window fill out all the fields and press the Submit button.

Thanks Jason and Justin! :)