I used Simh Vax, but I've also used Charon-VAX in the past when they were allowing free usage of the software (I don't know the current situation). Charon was

I used Simh Vax, but I've also used Charon-VAX in the past when they were allowing free usage of the software (I don't know the current situation). Charon was quite fast at the time on the hardware I had in maybe 2008 or so. But I've used Simh recently and it's plenty fast enough on modern hardware.