Actually, if you had a graphics card or a hefty WinUAE setup, Hollywood would be the best even though the GUI is sold separately. (The GUI is called "Hollywood Designer".) I'm pretty sure it doesn't support DCTV though.
Scala is probably the second-best. I've never used it but I've seen some presentations done with it.
AmigaVision would have made a great rapid application development toolkit. It's a pity that the source code got lost in the Commodore liquidation otherwise I'd have loved to have gotten my hands on it and fixed it up right with datatypes support and so on. But as it sits, it works with Kickstart 1.3 and newer and doesn't support any newer features than that. (On an AGA system it does do some 256 color images due to upward compatibility.)
