As far as the modern AMV community goes, it seems to me like Sony Vegas is the most popular program out there. Personally for me, I've always used/preferred Adobe Premiere. The fact that I can import my entire episode/movie into the program and edit with it from there, WITHOUT having to re-encode it to something way larger, is a really huge deal to me (I'm talking about running my source file through an AVS script and then importing that script directly into Premiere). It's the way I've worked for a very long time and I don't care to give it up.
You'll notice I'm not talking at all about the user interface or the various tools and effects and what-not that the 2 programs have. That stuff's always going to come down to your own personal tastes/opinion, or simply what you've gotten used to. At the end of the day, as far as being able to edit your video, they both do pretty much the same thing. So if I'm going to objectively pick one I'd recommend more, I'd go with Premiere purely on the fact that it can import AVS directly.
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