I always thought getting a signature sound would be something most musicians would aspire to create. I can think of so many famous signature sounds, none of them boring. Mostly a combination of style and tone. From Michale Jackson's voice to Brian May of Queen's guitar, all very recognizable. One of my favorite signature synth sounds would be Manfred Man's Minimoog tone. Been playing a Mini for 40+ years and could never quite nail that tone he gets. Yet he sounds so unique and could pick his style and tone out of any mix.
One of the few unique tones I have discovered was on my old modular Moog. Everyone knows what those ladder filter Moogs sound like, right? But the flexibility of patching allowed me to create a patch using a positive feedback loop from the 904B highpass filter. This crazy resonant squeal was the result, and using a pedal made a wah-wah type of controllable tone. Didn't make that typical Moog sound at all but something unique.
Here is a short sample.
One of a few signature sound for me? At least I'm trying.