Here are a few of my favourite PODs in WW2 (favourites because they rarely ever seem to appear in the usual course of events - of course that may just mean they aren't particularly feasible)
1/ No Battle of Britain. Hitler decides he isn't going to invade the UK and just blockades it - U Boats and bombing the channel convoys. In effect, for Britain to carry on the war, she has to take the offensive.
2/ Maybe tied in with the above. De Valera gives the Germans basing rights in the Free State, perhaps in exchange for the Six Counties in a subsequent post war peace treaty. How would US public opinion react to the knee-jerk invasion the British woud have to do?
3/ Mentioned in an earlier post - Japan only attacks the European Asian colonies. A big risk leaving the Philipines across the Lines of Communication but again would the US go to war to save the European empires?
4/ Instead of Midway, the Japanese invade Ceylon
5/ Anglo-French forces invade Norway just before the Germans do - it was a close run thing.
6/ Anglo-French forces try to bomb the Azeri oilfields to reduce the amount of oil Hitler's ally Stalin was shipping - again planned but wiser counsel prevailed
7/ Rashid Ali's coup in Iraq gets more effective German aid and leads to a wider arab revolt against the British
Any comments welcome