I will let you in a little secret of mine. I enjoy doing video editing. But since I don't have source material and one I have is shitty [VCD or below quality] I can't perform some masking functions and frame by frame edit. Since the source file has artifacts. But that doesn't stop me from trying things.
So, if you're into Video Editing then following softwares would be great for you.
Adobe Master Suite
Adobe Premiere Pro is a powerful video editing tool and After Effects is used for generating effects. They're both essential in making great videos.
Final Cut Pro
offers everything. Unfortunately it's only for Mac and I can't use it on Windows. So, if you're a Mac user, try that.
Sony Vegas is another Video editor which is preferred by many. I tend to use it some times since it offers great effects and it's easy to use. Plus, the Dfg Collage videos were edited in this software.
I used the HD version. It's a shame I don't have enough resources but even on my old P4 it performed quite well. It was easy but not that powerful if you're trying something different.
There are other open source alternatives out there but the above are the most used video editors. I have a Core2duo processors and it's the minimum requirement for using some of the above softwares if you're planning to edit HD. Plus, having 4GB or more RAM helps and a 64-bit System is essential for Adobe Suite.
All in all, even with the most powerful editor and PC you still need knowledge and some creativity and content to use these softwares. I wish I had an HD Camera. I could record Time Lapse videos and do all sorts of different things. But working with SD resolution doesn't offer you much since you can't add special effects and you take different shots you normally see standard videos.
If you're using a 64-bit OS then install both the 32-bit and 64-bit version. Trust me having those codecs save you tons of time.
- Adobe Media Encoder
I prefer Cyberlink Media Espresso and Adobe Media Encoder but they aren't that much flexible. In those situations I use Handbreak or SUPER. There are other alternatives out there as well.