It has to be the PPC cards.
If I had to pick only one, then CSPPC for sure.
Nah. They cost too much when new, the price only got worse, they're as fragile as eggshells, and they were limited to some of the worst-selling Amiga models ever (4000/1200).
I'd take a tricked out A2000 (yes, I know 120mhz "developer" PPC cards were released for the 2000, but what of it? There were five, maybe six? A dozen?) or desktop 1200 with all of the addons I mentioned before the PPC card.
Although I'd gladly sell the PPC card for more $ for addons!