The best hosting providers for Ruby are:

1. Heroku
2. Amazon Web Services (AWS)
3. DigitalOcean
4. Google Cloud Platform (GCP)
5. Microsoft Azure
6. Engine Yard
7. A2 Hosting
8. SiteGround
9. InMotion Hosting
10. DreamHost

These hosting providers are considered the best for Ruby because they offer robust infrastructure, good performance, and scalable resources to support Ruby applications.

Heroku, AWS, GCP, and Azure are considered to be more enterprise-level solutions, offering a wide range of services and tools for managing and deploying Ruby applications. DigitalOcean and Engine Yard are considered to be more specialized solutions, with a focus on Ruby on Rails.

A2 Hosting, SiteGround, InMotion Hosting, and DreamHost are popular options for shared hosting, offering a balance of performance, affordability, and features.

Ultimately, the choice of hosting provider will depend on the specific needs and requirements of each Ruby application, so it’s important to carefully consider the available options before making a decision.