Blame it on Rio. The Brazilian city seems to bring out the sizzle in Hollywood's hottest stars – including Hugh Jackman and Tom Cruise.  The Wolverine hunk, who was in Brazil promoting his blockbuster movie, showed off his guns at the Copacabana Beach hotel Wednesday. In February, a shirtless Cruise displayed his own six-pack at the same resort while vacationing with wife Katie Holmes and daughter Suri.  Tell us who do you think is the top gun?