Located in les Invalides in Paris, the Musée de l'Armée has a huge collection of militaria covering a huge range of time. I tried to grab a few of the pictures I thought might be most interesting to games/modelers. If you ever get a chance to go, it is well worth a day!
Medieval Era
Gunpowder Era
World War 1
Extra bonus picture of the tomb of Napoleon - of course I had to stop by to say hi!