<p>I'm starting a new web project and I am considering two presentation frameworks. I am thinking either about ASP.NET MVC or Silverlight. I would tend toward Silverlight since I'm quite experienced .NET developer while I have just a basic knowledge of ASP.NET controls.</p>

It's hard to recommend one over the other without knowing what your application is.  Whatever you do decide, make sure you keep your target audience in mind; not everyone is going to have Silverlight installed on their computers.
Personally, unless I was designing an incredibly interactive and beautiful web app, I would go with ASP.NET (with or without the MVC framework) if only for the fact that there is a
ton
of reference material for it while Silverlight is still relatively new territory.