well that depends on wether you want to make a good video, or just some youtub piece of crap.
Adobe premiere does a pretty nice job of track-matting, color screening, and 2D based color space. But at $6-700 money better spent on feces if all your doing is amving.
Magix is nice and in many cases under $100! Magix is the program I use to create many of my matted visual effects. A great program even if just as an addon to adboe/avid.
Brining us to our lesson on Avid. Avid is AWESOME. If not more. Liquid being the entry level program is sweet. but at $700 a bit on the pricey side.
Absolute best is Adobe After Effects. But its
FOUR FIGURES!!! yes, four frigures. However
http://www.adobe.com/ has a 30 day trial. is if fun. YES. Will it do this. Yes, AND more. You can crop out images 2d and 3d with fill control and feather in motion. You can remake "Money For Nothing" in 15 mintues with skill. Yes, its just that good!
Warning: This has a very high learning curve.