Menu > Settings > Applications > Manage applications > Samsung Apps. You'll have three options here... Off, Wi-Fi only or Packet data. Check the 'Off' button.
Then...
Menu > Settings > Applications > Manage applications, then select the Samsung app's you don't want and Uninstall them.
Because you stopped new Samsung app notification you wont get notifications for the app's you 'should' have on your phone.
The downside is no notifications of updates for the Samsung app's you want. But I just manually check via the Samsung Apps application and update if necessary.
Then...
Menu > Settings > Applications > Manage applications, then select the Samsung app's you don't want and Uninstall them.
Because you stopped new Samsung app notification you wont get notifications for the app's you 'should' have on your phone.
The downside is no notifications of updates for the Samsung app's you want. But I just manually check via the Samsung Apps application and update if necessary.