What is a good video making/editing software?

*Windows 7 64, 320GB drive space, 1.65 Ghz Daul-AMD-processor. Lenovo Laptop*

Given those specs of my Laptop, what would be a good video making and editing software. My goal is to take a bunch of clips from youtube and make a 'Buffy the Vampire Slayer' parody, but with a different person(and have them be a slayer). I want to remake the Buffy intro, using the theme song and make someone look like they were on the show.
What software would be best for doing that?

Thank you

Added (1).

This is the Buffy intro I want to make, but a parody.

Guest

Ulead studio 11.

Skyluck

I'd like to recommend HD video editor to you, I always use it to edit video and make funny video for uploading to Youtube, it's easy to use and the quality is awesome, you can crop, cut, join, edit video with it easily. It also embeds many special effects, you can even add text to video or add background music, that's pretty cool.

nicoleas

Introduce video eidtor to you, which is an easy tool but has powerful video editing functions, you can easily finish your video with the guide.
http://www.isoftatoz.com/article/how-to-edit-video.html

Colin