During a 16-year career, supersize slugger Jose Canseco belted 462 homers—but his most memorable shots may be those he takes in this controversial diss-and-tell. Recounting his own journey from dorky teen to MVP and Madonna boy toy, Canseco, 40—now unapologetic about a "juice" habit he denied during his playing days—opens the clubhouse door on what he contends was rampant use of anabolic steroids and human growth hormone while Major League Baseball looked the other way. Claiming to have injected steroids with ex-teammates including home run king Mark McGwire and Jason Giambi—who have denied his charges—Canseco says, "the challenge is to find a top player who hasn't [used steroids]." It's easy to write off Juiced as a form of 'roid rage, a final swing for the fences by a has-been. Tougher to dismiss are the few more credible sources who have so far come forward in support of some of Canseco's claims, including one FBI agent. Or, truth be told, our own eyes.