Yesterday, I decided to buy Mercenaries 2: World in Flames on PC direct download. I weighed the options and decided to buy it through Gamestop's direct download server. It had a vast selection of games to choose from for download as well as DLC for said games. The selection rivaled even Amazon and was comprehensive of modern games across genres. Prices were good and were even lowered to the points where, with tax added, it equaled or was less than the advertised price. The only drawback was the 4+ hour download time.
I would recommend using Gamestop for direct download