It really depends on what you mean by performing animations. If you're talking about animating items on a form, for instance, I'd look into using WPF or Silverlight if I were you. If, however, you're looking to perform a DirectX type of animation, then I'd spend some time getting into
XNA[
^] (which is easier to work with than bog standard DirectX), or you could look at OpenGL with
CsGL[
^].