My take:
 
  Initially, I started watching the show with my father.  After that, this fact kept me watching the show to a large extent, but the reason that I still enjoy the show is my interest in history in general and World War II in particular.  I am a big zealot regarding World War II.  If I had more time, I would know even more than I know now.  Considering that there is a historical perspective to Hogan's Heroes, it retains my interest.  The humor of the show comes through a number of channels.  Whether it's obscure references to the War or otherwise, I find the show intriguing.  When I have more time, I plan on finding all of the references in the show and relating them to the actual events.  For example, in one episode, LeBeau is going to be transferred to a camp called Colditz.  This camp actually existed in World War II, and coincidentally enough, it seemed a lot like Stalag 13 (the Heroes Camp).  That is, there were frequent escapes, there were prisoners running certain parts of the camp, and when liberated in 1945, the prisoners already had an extensive tunnel completed.  Facts like this just prime my interest in the show hopefully will do the same for you.  Feel free to go back to my World War II site which is still being worked on.

Plot and explanation:

    Back in 1965, the first Hogan's Heroes episode aired.  Most likely you already know the plot if you're at this site, but if not, hopefully you'll learn something.  Colonel Robert Hogan is the senior officer of the Prisoners of War in a German luftstalag in World War II.  In his gang are Corporal Newkirk, Sergeant Kinchloe/Sergeant Baker, Sergeant Carter, and Corporal LeBeau.  The heroes undergo many situations in their quest to make the war as troublesome as possible for the Germans.  These activities could be any number of things including but not restricted to
 

• 1)  sabotage of any and all German buildings, railroads, and other possessions
• 2)  contact with underground members of the anti-nazi germans in the area
• 3)  export of influential Germans by means of the underground to England
• 4)  convincing the Germans that an instrument is in fact dysfunctional

Part of the charm of the show is the general comedy to the show which, similar to some other shows, requires some immersion in the show.  In addition, a compartmentalization with respect to history is necessary for some viewers.  That is, the entire war and holocaust was a horrendous thing, and a sitcom about the show needs to be taken as anything but making a joke out of history.  The makers of the show have made sure not to include things that did make fun of the war in fact.  Questions, though, have come about the fact that two of the most main German characters, Colonel Klink and Sergeant Schultz, are lovable characters.  This, in fact, has been the point of much controversy in the past, and is part of the reason that the show didn't get bigger than it did (however it did get a very substantial audience during its 1965-1971 showing not to mention its audience in syndication).
    The Heroes have many things to their disposal including
 

• 1)  a home-made radio with which they contact and receive messages from London and otherwise
• 2)  a bug to Colonel Klink's (the camp kommandant) office by which they listen to conversations in order to determine appropriate actions
• 3) an extensive tunnel network which spans to nearly all of the barracks, administrative buildings, and outsde the barbed wire.
• 4)  access to all of Colonel Klink's facilities including the mail, the telephone (with their own switchboard in a tunnel)

  There are some key premises that must be understood in order to "get" the show and they include:

• 1)  since this whole situation occurs in a P.O.W. camp, we can expect to see much of the occurences to be realistic.  That is, the last place that the allies would bomb is a camp with their own countrymen.  Therefore, any planning for top secret testing, etc. could be logically done here.
• 2)  everyone on the cast has their own abilities.  Carter has the ability to use explosives as well as chemicals, Kinchloe has communication abilities regarding the radio, LeBeau finds ways to manipulate the Germans through their stomach through his culinary wizardry, and Newkirk is a pickpocket with other abilities.
• 3)  sergeant schultz may technically be on the german side, it is hard to believe.  Schultz describes himself as a neutral and in fact, does work with the Heroes in the sense that he is more ruled by his appetite than by his duties.
• 4)  the heroes can leave the camp at any time, but have promised to fight out the war from this side.

• 1)  Colonel Klink being voted top Kommandant of the week/month/year, whichever is necessary at the time
• 2)  Saving Klink and Schultz from being transferred since they can only keep up their operations in the camp as long as those two incompetants reside there.
• 3)  Avoiding the rules or problems created by General Burkhalter (above Klink in the military hierarchy), Major Hochstetter (Gestapo), and others who have authority over Klink.
• 4)  Dress-up of nearly all characters.  Any of the heroes dressed up or impersonating on the phone any number of people or schultz dressed as Klink, or Santa Claus, or others.