I work for Pinecone so my bias is obvious, but objectively: Pinecone is ranked as the most popular vector DB according to multiple sources [1][2][3][4], the best funded ($100M Series B), and is used in production by the likes of Shopify, Gong, Plaid, Zapier, Midjourney, CVS, and thousands of others.

[1] https://retool.com/reports/state-of-ai-2023

[2] https://state-of-llm.streamlit.app/#third

[3] https://db-engines.com/en/ranking/vector+dbms

[4] https://www.g2.com/categories/vector-database