1)    Support Services: This is one of the most important things which will have an impact on you application sooner or later. Do check for the existing support tickets and see the replies from the hosting service. Open a few random tickets and see how quickly the issues were resolved.

This will tell you a lot about the companies support system.

2)    Check for network latency of the web hosting company. This is very important as it will have a direct impact on the pages are served and your sites performance. Click here (PingPlotter)  to download a small software which shows the network latency and graphs.

Following are the best Hosting Services offering Rails support.

Hosting Rails (http://www.hostingrails.com) (My Pick #1 for Shared Rails Hosting)
Lot of gems are available on HostingRails server to be installed. If you don’t see a Rail Gem you want to install on the list, No Problem! Hosting Rails are happy to install it for you as long as it is listed on RubyForge.com and has no performance issues.

Offers good tutorials (http://www.hostingrails.com/tutorials) and has a huge repository of FAQ’s and Tickets which are available for our references.

Hosting Rails not only offer one of the best services in the industry but also best prices on their hosting plans. Shared hosting plans start from $2.88/Month to $15.99/Month

Dream Host: (http://www.dreamhost.com)
DreamHost is a known name in the hosting industry and stands as one of the best hosting services today (I am sure thousands of you will agree with that).

It offers plans under $10 if purchased the account for a year. It also offers very good online support, however, charges extra for limited phone support per month.

DreamHost  is currently running a discount offer on their hosting plans

    * To get the setup fee waived use the promo code "NoSetupFee"
    * To get the $50 discount use the promo code "Promo50"

DreamHost offers a huge list of Installed Gems on their servers. Click here (http://rails.dreamhosters.com/) to view the list of Gems on Dreamhost.

EngineYard (http://engineyard.com) (My #1 Pick for Dedicated Rails Hosting)
This is one of the most expensive services which offer exclusive Rails support. If its got anything to do with Rails and you need it then this service never says a NO, but there is no such things as free lunch.

All the additional applications come for a price tag.  Click here (http://engineyard.com/customers) to see what their customers have to say about them.

EngineYard offers best support and services for Rails. Click here (http://engineyard.com/whatyouget.html) to see what do you get with a plan.

Rails Machine (http://railsmachine.com/)
One of the best services you will find on the net. These are professionals and take their business and clients business seriously. RailsMachine offers high end services and solutions in terms of hardware and support and also charges handsomely.

(Dedicated Servers) Services start from $75/month + $30 setup to $325/month + $30 setup. This is the best plan if you can afford an expensive plan and looking for dedicated servers.

A2Hosting (http://www.a2hosting.com)
I am not very much familiar with the A2Hosting (excuse my ignorance), however, on papers A2Hosting looks like a good hosting company which offers excellent shared hosting plans and offers ruby support as well.

Pricing starts from $3.95 to $17.95 for a year long plan and it also offers a 30 Day money back guarantee.

I am pushing this hosting service down the list as I noticed high latency (at least in India).

I hope this helps anyone who is planning to purchase hosting for Rails Or if you know a better one please leave comments.