Overall i've found Gamersgate to be the "least" region specific. It is a european site [where Steam + D2D is USA] , so you are more likely to get the EU version of games on there. You will definitely notice they have German/Spanish/French versions of alot of games [something you won't see on Steam] .
I bought from them before, can't complain. It's not as integrated as Steam, and is more like Direct2Drive. For some it's a good thing (it means you don't need an app to launch games, and you download the game without any Steam-like "DRM") . They also got a nice "points" system, where you get points for every purchase, which implies you can use the points to buy game in the store, kinda like a "cash back" thing. So in some cases it can translate to a double discount if you use them alot.
