What do you get when you dress the Hulk in Captain America's clothes? A Star-Spangled Banner.

Why does Black Widow love sitting on Captain America's shield? Because it's made out of vibranium.

I think comic book bad guys have the right idea, aiming their weapons directly at Captain America's shield. That's probably his weak point.

If Captain America's shield is vibranium, then... Hawkeye's shield is Quicksilver