Aptoide - Aptoide is a third party replacement for the traditional Google Play Store.
F-Droid - F-Droid is an interesting alternative for Android users who want to try something different and not have to use the Goole Play store all the time.
Ninite - Ninite is the easiest way to install software.
APKStone - All apps in one place. Download APK files or from Google Play Store.
Amazon Appstore - The Amazon Appstore is a place to purchase and download apps for your Android device.
1Mobile Market - 1Mobile Market is one of the newest apps and games places where the exclusive download of games and apps is accessible.