It’s a very personal choice, and there are hundreds of them out there to try out - you could spend months auditioning software synth demos instead of actually making music! We say it’s a personal choice because you should pick a synth that fits you and the music you want to make, whether that’s how it sounds, how it feels, how steep the learning curve is, and if your computer’s CPU can even handle running it. Choosing what VST synth to use is not easy.