The American Prospect was founded by Robert Kuttner Obama's Challenge: America's Economic Crisis and the Power of a Transformative Presidency and Robert Reich Reason: Why Liberals Will Win the Battle for America, both important thinkers in their own right. While it isn't as radical as I think our analysis needs to be in this time of ecological and economic meltdown, The American Prospect is consistently thoughtful and provides a very helpful response to the endless barrage of right-wing PR in the service of corporatism and militarism The Corporation.
The current issue features a cover story on a constructive development in cable news, that is the rise of Rachel Maddow on MSNBC. Openly gay, and politically astute, Maddow is a breath of fresh-air on the tv tube which has been so dominated by men. The article notes that Maddow is currently working on a book about the militarization of the United States The Complex: How the Military Invades Our Everyday Lives. I'd like to see the American Prospect include the occassional radical like Angela Davis Abolition Democracy: Beyond Prisons, Torture, and Empire Interviews with Angela Y. Davis (Open Media), Michael Parenti Contrary Notions: The Michael Parenti Reader, or Winona LaDuke New Perspectives on Environmental Justice: Gender, Sexuality, and Activism. Nevertheless, the Prospect does a great job of responding to the misinformation efforts of journals like The Weakly Standard and the National Review.

See also:
Z Magazine
Plenty Magazine
Imperial Ambitions: Conversations on the Post-9/11 World (American Empire Project)
Utne
Mother Jones