Best place? If you can, I would recommend buying it from Amazon via the Subsim link here, because that way Amazon gets a cut of the sale
http://www.subsim.com/store.html
Otherwise, Steam is okay, but because it forces you to run the game via Steam (and creates problems if you want to modify the .exe, along with sticking the game in the Steam folder where it can be easy to confuse things with mods), I prefer other options first. Gamersgate (
http://www.gamersgate.com/DD-SH4GE/s...4-gold-edition ) is a good other option.