There are tons of modern tools, but IMO some of the best ones ever were the trackers and editors from Jens Christian Huus of The Vibrants. These guys always had some of the most amazing sounds, and the editors are at least somewhat friendly.
They also made Edlib (FM tracker for MSDOS) that is EXCELLENT for FM tunes. (probably second only to FM Composer)
Another great tool (and it’s not a SID, but makes similar sounds minus the analog filter) is the Glitch Storm from Spherical Sound. It’s cheap, simple, and not only makes great sounds, but rhythmic patterns. I generally run it into my Black Box, sample a few seconds, then chop out single hits. It can do just about anything “Chip” short of multi-operator FM type stuff.
Probably the BEST way though most expensive, is to find a SID Station. 
Another BEST way would be the ReFX QuadraSID VST. It’s a full SID VST, and is SUPER EASY to make sounds on, and then you can just dump the sounds digitally. I don’t think ReFX sells it anymore, but I have a license and don’t use it. I’ll see if I can dig up the info, and an installer for it. I’d be happy to pass it your way since I haven’t touched it in years.
I have a knack for that!)