Another fun one is the Cuban Missile War timeline, a frightening alternate history of the Cuban Missile Crisis turned into nuclear war. I'm not an expert, but my impression is that it's pretty realistic.
The timeline diverges from reality when a Soviet submarine captain launches a nuclear torpedo at an American ship, which then gradually spirals into all-out nuclear war. This very nearly actually happened: the three main officers on the submarine had to unanimously agree to use nuclear weapons, and two of them were in favor. The third one managed to talk them down.
That reminds me of the novel Resurrection Day, which is set 10 years after a global war over Cuba and has a damaged US run as a miltary dictatorship and pretty much an international pariah due to the extent of the US attack on the Soviets (e.g. surviving members of SAC are regarded as war criminals).
Not a bad book - my main nitpick with it being that its scenario has Western Europe coming off fairly untouched by the war which would have been extremely unlikely.
I read Command and Control in the span of a week (fast for me) over the Christmas holiday the other month, and it was enlightening (read: scary as hell that we for the most part lucked out not having a nuclear dead zone in the middle of the USA at this point in time).
One thing I did take away: the military kept using more extreme and dangerous measures (mainly in my mind the fully loaded bombers circling 24x7 over Europe) with the military trying to install fail-deadly mission objectives (ie: circle Europe for your daily bombing run, and if you don't hear an all clear message, assume the USA is being attacked and bomb the Soviet Union). One point seemed to be made though was: for all of the idiocy and lack of control during the arms race there were no actual nuclear detonations, so were the weapons at the time actually safe (even though many improved safety mechanisms were ignored by the military), or was it just luck due to small-enough sample size and a luckily short enough time span?
I actually ordered off of Amazon these two books cited by Schossler and just received them in the last two weeks and am really looking forward to reading them:
The Making of the Atomic Bomb - Richard Rhodes:
~900 page book that is supposed to be the seminal book about the history of the bomb; also is apparently very detailed in the physics of the endeavor which should be very interesting.
Dark Sun: The Making of the Hydrogen Bomb by Richard Rhodes is the follow up to The Making of the Atomic Bomb and is even more interesting as it tells the story of the Soviet bomb project at the same time as the US H-bomb project:
http://www.alternatehistory.com/discussion/showthread.php?t=...
The timeline diverges from reality when a Soviet submarine captain launches a nuclear torpedo at an American ship, which then gradually spirals into all-out nuclear war. This very nearly actually happened: the three main officers on the submarine had to unanimously agree to use nuclear weapons, and two of them were in favor. The third one managed to talk them down.