I learnt basic battlefield planning from games, and have used that quick planning skill in exercises in my job.
I also am damn good at map reading skills from all the varying degrees of maps found in games! Especially games like GTA and the Getaway with the hard-copy maps that you can use while playing! Now maps are second nature to me, even home made hand drawn and confusing ones!
Finally I learnt aircraft recognition from the Act Combat games, along with some of the basic characteristics! Like the SU-32, and the fact it has a kitchen and tiolet on board, even though it looks like a fast jet, and you enter it through a ladder behind the front wheel!