Thank you for this question!
According to a survey we conducted a while ago:
1. Plans & prices (hosting types, hardware, type of virtualization, bandwidth)
2. Service value (what you got for your budget: cPanel, managed or not, back up)
3. Equipment & Data center-class
4. Uptime
5. Network infrastructure and uplinks
6. Support & feedback system
7. Additional services (individual server configuration, DDoS-protection, data warehouse etc.)
8. Reviews about the hosting provider and quality of technical support
9. Price-off & promo
10. Brand (everything connected with a name, design, and history of a company)