THE CLASSIC COMIC BOOK/USO COSTUME

This is the costume that most people are familiar with and the one that all the others are based on. The Classic Comic Book costume has endured for 70 years, all the other costumes came after. This is the second Jack Kirby costume, the USO version from the film The First Avenger and the one that has been in the comics for decades.
Red leather gloves, red leather cuffed boots, blue trousers with no pockets, black belt, either plain costumed or armored shirt, cowl/mask with wings and stylized 'A'. Iconic round 'Bullseye' shield.

Strictly speaking I separate the Classic Comic Book costume from the very similar Classic WWII Kirby costume because the original version had the 'Heater' shield and no cowl even though they were both designed by Jack Kirby and both were worn during WWII.
The more typical cowl version with the more famous round shield was designed soon after the initial costume and stuck until the end of the war. And when Cap was re-awoken in Avengers Vol. 1 issue 4 in 1963 (or movie timeline 2010) they design stayed.
Technically the latter USO/Classic Comic Book costume was also part of the WWII era and it was great to see it in the movie, but if the director wanted to be correct to the history of the comics he should have left the cowl part of the mask off until Steve received the round shield.
But instead they went with a completely new design for First Avenger and that is covered in the FIRST AVENGER COSTUME section of this site.
The Classic Comic Book uniform is my personal favorite although I think its the most difficult to pull off well in reality. Not many resources for red leather pirate boots or classic cowl/masks exist. It's something that has for the most part be custom made. And even fewer people in good enough shape to fill the so-called 'tights'.

1.  http://www.emerchandise.com/captain-america-stars-and-stripes-cut-and-sew-t-shirt?id=tscapstrsstripes