It all depends on where I was fighting and what my objective was.

For a rifle, I'd be using either an M1 Garand (with bayonet), or a Lee-Enfield.
For a submachine gun I'd probably use an M1A1 Thompson or a PPSh-41, both with drums instead of box magazines.
For a machine gun, I'd have a Browning 1919 or MG42.

And I'd just have a normal COLT 1911 for a side arm.