REA-Plugins

 

ReBirth RB-338 is eternal.

 

for me, its MDrummer, using it since version 1

 

100% Vintage warmer has lived on my Mix buss for well over 10 years now. Just barely tapping into it, it just glues things so nicely.

 

Serum, now Serum 2. Hugely influential in modern music. Excellent feature set, easy to use, massive community and presets available. Free update, nice developer.

 

I don't think popularity is a relevant metric, standing the test of time is also irrelevant, you may actually want the opposite in many cases - bad sounding stuff with unique character that's not overused by everyone in the genre.
About sound quality - you can take a synth from mid 2000s and use high sample rate project in your DAW, so there is no aliasing. The sound quality would be similar to modern synths, while the CPU hit would be many-many times smaller.
Ease of programming is important, though. While Serum 1 has smaller sound design range than something like Zebra 2, programming the second and getting good sounds is way harder, one of the reasons why this synth was so obscure and gained popularity only in soundtrack genre after Hans Zimmer basically promoted it.

 

Diva , kontakt , Taqs.im Solo , Kirchhoff EQ , Orion,God Particle

 

Sonalksis, DMG

 

Fabfilter imo

 

DMG EQuilibrium

 

waldorf a1 & attack

 

not only you appreciate plugin that can be used in amount of genres that can be counted on 1 hand, but also not v3, with updated spectral engine

this plugin should be buried deep into the ground and you know it

 

TC Electronic VSS4 HD, VSS3, NONLIN 2

 

Sonnox Oxford Inflator
PSP vintage Warmer
Decapitator Soundtoys
but hey... wtf will stand in the near future if no computer can load them back
" (

OP will have to go back in the cave and redo from scratch and scracth the cave until new song reappears