6 weapons the US military should bring back from the dead

I've fired 4 of the six in my life time. All are good weapons, if I were to recommend one system to be brought back, it would have to be the quad-50.

I understand that the Ontos primary kill mechanisms in order of highest lethality were
1) Standing behind it
2) Fear
3) The projectiles

How about an all-time favorite the M-2 Flamethrower?