I think it depends what kind of quilts you want to make. I bought my Accuquilt primarily because I wanted to try some quilts that use curved piecing, that I didn't want to have to cut by hand. If that's your goal, then look at apple cores, Drunkards path, Winding Ways, etc. If you like the look of half square triangles, then buy the HST dies. If you use strip sets, then get dies for strips of your favourite widths.
If you buy dies based on thevquilts you want to make, you can't go wrong . Good luck!