Short answer

• According to recent independent surveys and regulator data, the traditional banks most often rated highest for service quality are Itaú, Bradesco and Santander (Itaú usually top). (valorinveste.globo.com)
• Regulators’ complaint‑based rankings (Procon / Banco Central data) tell a different but important story: several large banks (Itaú, Bradesco, Caixa, Santander and Banco do Brasil) appear frequently among the most‑reported in 2024–2025, while some digital banks (e.g., Inter, C6, PagBank) also show high complaint rates when adjusted per million customers. Use both types of measures when judging service. (FocusTheAlpha.com)

What those findings mean (how to read them)

• “Best customer service” can be measured two ways: customer‑perception surveys (satisfaction/quality indexes) and complaint‑rate data from regulators. Surveys capture perceived quality and experience (phone/app/branch). Complaint rates show how often problems escalate to official complaints. Both are useful and sometimes conflict. (valorinveste.globo.com)

Practical guidance for choosing a bank for a personal account

• If you prioritize in‑person service and broad branch/ATM coverage: consider Itaú, Bradesco or Santander — they score well on service indexes and have large branch networks. (valorinveste.globo.com)
• If you want best mobile/app experience: many customers prefer digital banks (Nubank, Inter, C6) for UX and speed — but check complaint rates and recent news because large user bases can generate proportionally high complaint counts. (Reuters.com)
• If dispute handling matters: review the Banco Central / local Procon complaint rankings for the most recent year for the banks you’re considering (they report complaints per 1 million customers). High complaint counts don’t always mean poor service, but a consistent pattern across sources is a red flag. (FocusTheAlpha.com)
• Match features to needs: compare fees, branch/ATM access, card limits, transfer limits, and how easy it is to reach a real person (chat wait times, priority channels). Complaints often involve billing errors, blocked cards or lack of resolution — check how each bank resolves those issues in practice. (Meon.com.br)

If you want, I can:

• Pull the latest customer‑satisfaction ranking (FGV/Toluna or other surveys) and the Banco Central / Procon complaint lists for 2024–2025 and show a side‑by‑side comparison for the banks you care about.