Personally I think the Honey Bee (sometimes labeled Competition Pro) pads for CD32 are best for Amiga gaming. They're quite rare and expensive nowadays (got one from ebay for ~40Eur) but I think its worth it.
While I think the Playstation2/3 controllers might probably be the best controllers in the world for modern day gaming(i.e. using analog sticks for steering) I never really liked the concept of having seperate buttons instead of a cross for digital control.
