If you want to boost your calculations in Excel, then yes, learn VB (or VBA). If you want to make console apps or anything that starts to get more complicated then you don't really need to start with VB, just go straight to C or C++, or Java, or any of that stuff.
Yes, VB is excellent. Its nice and easy. Its most exciting feature is that it is an RAD (Rapid Application Development) tool. If You want to create window based applications (with GUI and buttons, textboxes and etc) its the best.
And by the way, I would recommend learning VB.NET instead of VB6.
Visual basic will be able to make games and such, but because it's a RAD it lacks some of the in-depth commands c++ has... it depends how good you want your game to be, or if you want your programs to be useful AND optimized.