is there any software which is project based to make programming fun for a teenager?

define ‘fun’

well more interesting than the exercises in visual basic

Alice is a teaching tool for introductory computing. It uses 3D graphics and a drag-and-drop interface to facilitate a more engaging, less frustrating first programming experience. And its free to download and use.

Its a project that was created by Carnegie Mellon University, with support from EA Games.

Good Luck!
R

I would say try Alice. Apart from that you could look into doing programming for LEGO Mindstorms. Last I recall they had a sort of visual/friendly interface for doing some of the basic programming for it.