I have found that the similarities between America's golden boy, Captain America, and a video game legend, Master Chief to be quite remarkable.  
 
For example: 
Both are soldiers 
Both are genetically enhanced 
Both are trying to save mankind  
Both have special suits or weapons  
Both become heroes in a time of war --  World War II and the War of the Covenant.  
Both wind of sleeping for extended periods of time before they are needed (according to the Captain America movie)
 
Of course the story lines are different as well as time periods, but the parallels are there. 

They have some things in common such as being super soldiers.  But their personalities are radically different.  Captain America is more of a symbol and has that patriotic aura while Chief seems to accept the fact that his sole purpose in life is fight for humanity.  He even goes into cryogenic sleep whenever he's not on a mission.  Also Captain America is mainly loyal to the United States while Chief seems to represent all of humanity.  
 
The only time that Captain America was in a large period of sleep was before the Avengers found him frozen in ice back in the 60's [real time]. When Captain America isn't fighting he doesn't go back to being frozen in a block of ice. 

I would like to point out that the only reason that Master Chief is loyal to all humanity is because it is world against world. As for Captain America's battles which are between countries. I would also like to prove that everytime Captain America and the Avengers fight A.I.M., Hydra, or any other global threat, they are fighting to save the world, just like Master Chief. So there is no difference between the reason that either of them fight.

The same could be said for Commander Shepard (Mass Effect series) As well. All three are 
 
1: Soldiers 
2: Enhanced (Cap's Serum, Master Chief's suit and Shepard's Cybernetics) 
3: Have special suits or weapons 
4:  All have become heroes in a time of war --  (Cap World War II, Master Chief War of the Covenant. Shepard Attack on Eden Prime) 
5: Gone for extended periods of time (Cap was frozen, Master Chief was in stasis, and Shepard was dead) 
 
and in the case of Shepard and Captain America both are great leaders whose followers would and have followed them on suicide missions.