How do I maintain hd quality from cam...

How do I get the video files from my harddrive on my canon vixia hg21 with the same hd quality on my computer? The files transfer as .mts files and I convert them with Any Video Converter, but when I try to edit them, they look choppy and the sound is not that great. When I play them directly on my plasma they look amazing. I just want the same quality on my computer, have the ability to edit them and make a DVD with them. I have tried Camtasia, Corel Video Studio 2010 and Microsoft Movie Maker.
Help,
Brigette :)