I also loved spitfire. For me it sounds great.
In case of chiptune there are free options if you make music on windows.
https://hiphopmakers.com/best-free-chiptune-vst-plugins
Some kontakt libraries also for chiptune:
https://impactsoundworks.com/product/insidious/
https://impactsoundworks.com/product/super-audio-boy/
https://impactsoundworks.com/product/super-audio-cart/
And also plogue has really great VST's (paid)
An alternative with plogue VST sforzando (free) is download soundfonts for using it into the soundfont sampler. But take care of some copyright issues.
https://musical-artifacts.com/artifacts?formats=sf2&tags=chiptune