What are the best video editing softwares for windows?

i have the same exact problem! i want to make a twilight video but i don't even know how to upload videos from youtube to Windows Movie Maker. If I find out, ill answer your question. I have searched for a good video flv download editing software for a long time, but I've never found the right one. I just need some suggestions on a good video editing softwares that I can download and try myself. Since the Final Cut programs are only for macs (I have a windows computer), I can't get them. And they are some of the flv to 3gp best programs you can get. Any suggestions are appreciated.