Welcome to the dark side. 
Several things that I rely on heavily (though you may not find any use for, depending on your process):
ZynAddSubFX is a strange but pretty powerful software synth. Iām currently using the Yoshimi fork of the project, though the main project was just revived and given a new UI called Zyn-Fusion that looks pretty appealing.
Sooperlooper is great for live looping, though if youāre already doing Pd and SuperCollider, I assume you may have rolled your own solution for that.
The Calf Studio suite of plugins are great, I use them particularly for EQ, compression, and other mastering-related stuff.
Helm is a synth thatās pretty new to me ā somewhat traditional subtractive-ish, with some extra bells and whistles and interesting modulation options, and the UI is nice.