NB The development team has a blog post here:
I will add to this list as I come across sites that work on the N97. Please leave a comment if you would like to suggest a site that you know works well on Symbian S60.
UPDATE: I note from the dev team post here that there is an issue with the HTML hosting of Silverlight on N97 devices.
NB I have asked the team who look after the Community Samples at Silverlight.Net if they would update the hosting code for Sl1 & 2 based samples.
Update: My Bad, they are only pointing to the contributions, not hosting them as I had originally thought.