Hi guys,
I don't visit Amiga.Org that often due to some huge projects I'm working on (currently archiving the Yahoo AMOS-LIST message archives and uploading them to Aminet).
Anyway, for me AMOS (AMOS Pro 2.X to be precise) is both easy to get into and allows for experienced programmers to include assembly (ASM) code, mess with the copperlist (needed for visual effects such as simple horizontal reflections) and much more.
If you get an Amiga emulator to run on your PC, then you can run AMOS Pro on that. I tried Blitz once and hated it, but that was an early version.
Try both, you can probably download them for free somewhere and then buy manuals etc. for the one you prefer the most.
Regards,
Lonewolf10