The Center for Digital Government is a thinktank/consultancy. I'm not sure how useful their research-for hire is to their target market of "government, industry and education leaders," but I enjoyed the (free) reports on top Digital Cities and Digital States, and the general Best of the Web awards.

They are in the process of compiling the 2003 awards, but you can take a look at the 2002 winners.

Some of the criteria for sites being judged were:

• A visible privacy statement
  
• Actual online services, so that citizens can complete transactions online from start to finish
  
• A policy for abiding by the W3C accessibility standards
  
• Innovation and use of Web-based online technology to deliver government or education services (what is new or cutting edge about the site).
  
• Efficiency or time saved (internally, or citizen use)
  
• Economy or money saved
  
• Usability of the website