If you go Orr for Hockey, then you have to go Koufax for baseball. While Bobby Orr is arguably the most talented player ever to play, he played what twelve years? And only eight great ones. Same with Koufax. He was the best pitcher ever - for six years. Kind of like Pedro too, but longevity wise, he didn't last. I think you have to take into account longevity when you say best ever. It is also why I think Lebron surpasses Bird for best SF ever. He will play far longer, and be far more dominant for a longer period of time, though I think Bird overall was a superior basketball player.
Hockey: Gretzky
Baseball: Willie Mays
Basketball: Bill Russell
Football: Lawrence Taylor
Speaking of best BB starting line-up. Magic, Michael, Lebron, Bill Russell (at the 4!) and Wilt. Bird Sixth man.