Mostly nexus, morphine and tyrellN6 (all free), but the key to making real unique loops is to record a melody into edison and then mess around as much as you can with effects, time stretch, pitch stretch etc. Try out that method and see what you come up with works well for me
on CuBeatz x Travis Scott Detuned Synth by scottfarrell
on Ghost Town - Sad Spanish Guitar type loop by KiestyleProductions
Mainly used kontakt for the last 5 loops I posted