Video Editing Software - What do you use?

I'm interested in what video editing software people use. I only use Windows Moviemaker, but it is slow and not very precise but it is FREE
I have seen some great videos with excellent editing and effects like split screen (I'd love that) and more. So, what do you use, why and what 'couldn't do without' effects does it have?

Tony

http://www.desktop-video-guide.com/top-5-free-video-editing-software-review.html

have a look at this

peace :cheers: and beer

Here are some more threads you may find interesting:

http://www.ukuleleunderground.com/forum/showthread.php?t=10018

http://www.ukuleleunderground.com/forum/showthread.php?t=8833

http://www.ukuleleunderground.com/forum/showthread.php?t=9883

Thanks guys