Nearly a full decade after the Sept. 11 attacks, Osama bin Laden was killed by U.S. forces in Pakistan. But there remain many terrorists at large, and U.S. forces are still on the hunt for honchos from Al Qaeda and the Taliban. With the help of Bruce Hoffman, author of Inside Terrorism, NEWSWEEK compiled the "most wanted" terror chiefs yet to be caught or killed—along with what puts them at the top of the list.