Good Idea: Enhancing the feel of your Champions game by using Danny Elfman's themes for "Batman", "The Flash" and "Spider-Man".
Bad Idea: Enhancing the feel of your Dark Champions game by using Danny Elfman's theme for "The Simpsons".
And not Hero, but...
Good Idea: Charging into melee combat with a bunch of gun-weilding mooks in Feng Shui.
Bad Idea: Charging into melee combat with a bunch of gun-weilding mooks in Shadowrun.
(I've done it in both systems, so I speak from experience)