Nice Question!
Well short answer:
1. A unified Germany ruled by Soviet Union, occupation of Austria, Yugoslavia, Finland by Russia.
2. Western allies much weaker, at end of war.
3. USA adopts a Pacific century policy for remainder of 20th century.
4. China doesn't go communist straight away but Chinese Civil war continues for much longer (Nationalists backed by much bigger US Forces and supplies.)
5. No European union, France, Italy, Spain etc more socialist than historically.
6. UK Isolated and devastated by costs of war loses colonies/empire in same time - never recovers strength.