VCVRack, Softube Modular, Cherry Audio Voltage Modular
For those of us not ready to jump into Eurorack, there's always the virtual option. (Personally I'd love to have some kind of system that had both).
VCVRack is free open source and an amaxzing amount of plugins. It doesn't have to be the best ot be the one thatt everything else will be comapred to.
In this regard I would guess that Softube would offer a better sound with libereral use of oversampling and accurate emulations for a premium price. No third party developers but top noth patchers like Buchla.
On the other hand Cherry orchard while not open source does offer third party developers an opportunity, so you'sd expet some crossover withj VCVrack such as Vurt and his amazing filters and oscilators