Newtek
Scala
AT&T (license)
the reason I say NewTek is because over here Amigas major market was video-editing and 3D wich was of course Lightwave and the Video Toaster to a lesser extent TV-Paint and Digiview
the reason I say Scala is another major selling point was the kiosk market wich amigas filled quite nicely... scala multimedia fit the bill perfect
and finally the reason I say AT&T was that Amigas biggest sale ever was to the US Government if I recall and they used amigas because they could run Unix and X...and where reasonably priced (considering) I believe it was 30,000 units in one sale? I'm not sure... alot of others deserve mention...but I dont think anyone contributed more then these three in terms of helping the platform and bringing us new technology.