A recent MediaWeek article outlined the Top 30 Newspaper Websites in April, 2008 - noting that only seven of the websites showed a decrease in traffic from last year. Here's a list of the top 30, as provided by Nielson Online to MediaPost:

NYTimes.com
USATODAY.com
Washingtonpost.com
Los Angeles Times
Wall Street Journal Online
Boston.com
SFGate.com/San Francisco Chronicle
New York Post
Chicago Tribune
Daily News Online Edition
Atlanta Journal-Constitution
Chicago Sun-Times
Newsday
DallasNews.com - The Dallas Morning News
The Houston Chronicle
International Herald Tribune
Seattle Post-Intelligencer
The Politico
MercuryNews.com
The Seattle Times
The Sun, Baltimore
Azcentral.com
The Washington Times
Village Voice Media
Philly.com
Star Tribune
NJ.com
St. Louis Post Dispatch
The San Diego Union-Tribune
OregonLive.com