If you are interested in the personal stories of those involved in WWII, then the BBC has archived a large number here:
BBC - WW2 People's War - About this site
The site is conceptually well organised: service, area, place etc., but they have scewed stuff up so badly that the internal references don't follow one after one. To make sense of it you may need to use a search engine ''site BBC....'' etc.
I was able to use this to make sense of my father's war record. RA anti-aircraft, London, North Africa, Italy.
Edit. Adding to Strake's comment above, this isn't all allied stuff. There are views from prisoners, and the other side too.