With no Mac, what PC tools does one need to create high-quality web video?

Hey guys, I'm relatively new to web video production so wanted the opinion of web video editing buffs here ;)

Here's the type of web-video I'm after:

http://www.youtube.com/watch?v=R_QNC...layer_embedded
(fun video introducing Groupon's features)

Millionaire Society (fun video presentation for work-from-home enthusiasts)


Let's assume I have no Mac.

Precisely what are the most cost-effective PC (Windows 7 or XP) tools you would need to produce video presentations of at least the same QUALITY as those - as if I had a Mac?

Any extra hardware that's needed beyond a simple microphone?

From some guys, I keep hearing that you need a Mac.

This is assuming you have all the still-image graphics needed ready.

Thanks so much for the insight.