Flame has the most extensive set of both creative and technical tools, but what amazes me is not just the individual tools but the techniques that Flame Artists invent to solve complex compositing challenges. I learned this technique from Paul Rosckes in Chicago when we were going over new features and he asked me a simple question, "Did you ever wonder why there is a Camera node in the GMask Schematic View?"
As a 3D compositor, Flame has hidden functionality that might not be obvious. For example, you might not have realized you could apply textures (reflections, wraps, etc.) to just about anything – including a flat image. This video explains this powerful functionality within Flame’s Action module.