I'd probably consider Symphonic Rain one of the "best ones from Steam", but idk what people actually know about. This one is a binch because the fan translation has significantly better text for the most part, but is annoying to figure out; the Symphonic Rain discord might be able to help you. Other than that, I recommend Soundless for an honest-to-god denpa game, Pale Cachexia for a gothic horror with deftly written emotional development, Actual Sunlight for a crushing an uncompromising look at depression, and for untranslated VNs, I will always recommend the SRPG/VN hybrid Shinsetsu Mahou Shoujo, with a large cast of vibrant characters, a dark sci-fi plot that goes MUCH further than you expect it to — which is not to say it's not funny at times — and excellent gameplay to boot.