There's no rust on this baby. Iron Man kicks off summer on a blazing high note and practically dares the competition to measure up. It's been years since a movie superhero was this fierce and this funny. All praise to acting dynamo Robert Downey Jr., who brings so much creative juice to the party that Iron Man achieves instant liftoff. Even if you know diddly about the character Marvel built in 1963, Downey and director Jon Favreau — just the right swinger for the job — will get you up to speed pronto.