I started out using TurboSketch n/k/a IDX Renditioner, and I thought it did a good job of rendering each image. It's a plug-in, so it's convenient and very easy to use and has a good support forum. But since my purpose is to create Flash animations, I would have to manually render each frame of the animation. Since I've gotten Twilight Render I have used that for my renders, since it will automatically render the animation frames based on the scenes in SU. It's also a plug-in and very convenient and easy to use, and has a good support forum.