there is a game called command and conquer: red aleert...it is a real time strategy game...basically the premise is that Einstein some how goes back in time and assassinated Hitler when Hitler is still in school...and then the Holocaust never occurred...but what does happen is that Stalin sends the Red Army out all across Europe, conquering nations left and right.

there is also a series of Alternate History books by Harry Turtledove...it starts out in the middle of the Civil War...where a mesenger is carrying battle plans drawn out by General Lee hidden in a cigar...well the mesenger drops it...and some one points it out to him that he dropped it (in reality the cigars were lost and found by the Union Army) and so the CSA wins...and they USA and the CSA fight again 20-30 years later and the CSA wins again....then the Great WAr comes...and trenches are dug all along the the country...the USA allies itself with the Kaiser...the CSA with France and England...this time the CSA, France and England lose the war...and the USA takes huge chunks of Canada...and parts of the CSA as well...the CSA slowly recovers things start looking good...until 1929...the start of the Great Depression...then the CSA starts giving way to the rise of fascism...and Socialists are in the White House.