ArKaos is my favorite video software. I use it with a MIDI sequencer (cubase SX) to make my music video clips. It's really easy & efficient and the VJ 3.0.2 (release 3 weeks ago) makes it even more usable in my environement.
Easy to use from the beginning, and provides advanced features that you discover later, it's really fast & instinctive.
The only bad aspect is the interface, but I haven't found the same usability in another soft to scratch movies, set position, scratch or distort movies so fastly !!

thanks guyz