Does anyone play the Hearts of Iron series released on PC by Paradox?
It's a strategy real-time game set during World War II and you can play any of the world's nations - from USA and Germany right down to small countries like Luxembourg and Albania.
I spend hours on this game. You can play the entire period from 1936-1953, or choose to play individual scenarios such as D-Day or Barbarossa.
You can research technology and build rockets and eventually atomic bombs.
If anyone wants to know more I can post some screenshots tomorrow.