According to Longbox Graveyard, some enemies of Captain America include the Grand Director, Doctor Faustus, MODOK, Batroc, the Winter Soldier and the Red Skull. Each enemy boasts his own set of skills or powers.
The Grand Doctor
The Grand Director is described as a "paranoid, ultra-patriotic double" of Captain America. In a past comic, the Grand Director was given a Super Soldier serum that drove him mad and caused him to betray everything he loved.
Doctor Faustus is a mind-controlling neo-Nazi. He is also the enemy who caused the Grand Director to turn into an enemy of Captain America. Doctor Faustus first appeared in "Captain America" #107 and has an iconic monocle and Austrian accent.
MODOK, the Mental Organism Designed Only for Killing, is an enemy recognized for his large head. MODOK uses his brain to control, fight and destroy his prey.
Batroc is a recurring enemy for Captain America who uses his power of French foot fighting to attack. Batroc is considered a light-hearted and silly enemy.
The Winter Soldier
The Winter Soldier, formerly known as Bucky, is a sleeper agent assassin of the Cold War. The Winter Soldier is now considered a hero, but he began as one of Captain America's greatest foes.
The Red Skull
Captain America's arch-nemesis, The Red Skull, is one of the most popular enemies created by the Marvel Universe. The Red Skull appeared first in "Captain America" #1; in later comics, he is identified as a creation of Adolf Hitler.