As Andrewmentions, we have enjoyed following the CLR Team Tours this week on Channel 9:
Jason Zander - Tour of the .NET CLR team
http://channel9.msdn.com/ShowPost.aspx?PostID=29506
The .NET CLR Team Tour, Part II
http://channel9.msdn.com/ShowPost.aspx?PostID=29705
The .NET CLR Team Tour, Part III
http://channel9.msdn.com/ShowPost.aspx?PostID=29846
Of the various teams at Microsoft, if I was looking (I enjoy being independent and owning my own company), I would most like to be on the Indigo team (check out their tour as well), the CLR team, or one of the various Security teams. These teams look like great places to work!