(only apps, no games here)
1.EA (duh)
2.SAS (without Lattice/SAS-C there wouldn't
be that much SW to talk about).
3.Maxon/HiSoft (eventhough their C++ sucked)
4.H&P (mainly for StormC, the 1st user-friendly
C++-compiler.
6.VGR/Phase5 (CyberGraphX was and is the best
RTG-SW, and without it GFX-cards would never have
catched on)
I also aggree with Tigger on Hyperion, as there
games are nothing to write home about (they are just
reducing the gap to the PC, nothing more).
OS4 has most certainly allready changed Amiga-history,
but sofar not to the better, and wether it will
when it is released is yet to be seen.