Synthesizer V is widely considered the modern gold standard for realism. While the "Pro" editor and full voicebanks are paid, the Synthesizer V Studio Basic editor is perpetually free. Kasane Teto
If you have 5 minutes:
Eleanor Forte (Lite): A high-quality English female voice available for free as a "Lite" version. free vocaloid voicebanks top
While technically not a Yamaha Vocaloid, Synthesizer V by Dreamtonics has become the industry standard for free singing synthesis. Their "Basic" version is completely free to use commercially and non-commercially. Synthesizer V is widely considered the modern gold
Not worth the hassle unless you already own Vocaloid editor. If you have 5 minutes: Eleanor Forte (Lite)
Most free banks are female. Matsudappoiyo (or “Poiyo”) is a soft, breathy male tenor perfect for slower songs or duets with Teto. His VCV bank is exceptionally smooth.
Because the community often uses "Vocaloid" as a catch-all term, the most famous "free Vocaloids" are actually voicebanks. These are 100% free and community-driven. Synthesizer V