As a creative tool (Dpaint, Digiview, AMOS etc) I think the Amiga has no rival even today but due to such low standards set by people like US Gold and Ocean for a huge percentage of their released games I have to say the C64 is a more pleasurable experience trawling through thousands of games in the back catalogue than the Amiga TOSECs provide me.
Although there are still some gems I find for Amiga like the PD Asteroids carbon copy which is awesome.