In a market bloated with 'emulations' of classic gear, it's rare to find juicy sounding plugins that capture the best qualities of 'classic', offer some flexibility and don't break the bank. In the universe of more tweakable plugins, here too only a few offerings stand out.
After years of working with hundreds of plugins from numerous companies, I've found only a handful of offerings that keep me coming back. One of those companies that still hold a top spot is Voxengo. Their plugins are 'analog' without being slavishly limited to a given hardware model; flexible but not overloaded with 'feature bloat'; affordable without sacrificing sound quality; and have excellent & consistent GUIs to work with. A winning combination.
There is definitely a place for well designed emulations of classic gear, but when you require some flexibility and/or modernity, Voxengo is great choice. Their uniform GUIs also promote actually listening to the music!
Voxengo also has an easy robust activation system (no dongles), exceptional reliability (I've never had a Voxengo plugin crash my DAW in 14 years) and full 64 bit floating point processing*.
I have been a Voxengo user for many years after looking for a software phase alignment tool to help with mixing recordings of live shows. I use the PHA-979 as my go to phase tool for several years and it has been great for aligning guitar mics to D.I. sources in numerous live recordings I have made. I use a Radial Phazer live so having a bit of software that achieves the same result easily is a boon.
I'm also a big fan of Old Skool Reverb which sits happily amongst my vast arsenal of hardware and software effects.