Support is definitely the most important factor. Round the clock availability of support is also a feature that most clients look out for. I guess most people grow impatient when they see their site down. So 24x7 support is a must for quality hosting.
Also, proper guidelines with respect to money back garuntee, read the reviews in internet of same host. I will also prefer for flexibility in choosing right plans for you.
What you expect from your host must begin with what you paid for in the first place.
If you paid for an unmanaged server, then all that you should expect is that your host keeps the hardware running in good order. Do not expect your host to install anything for you or answer questions about matters which has got nothing to do with the hardware which the host provided.
If you paid for a managed server, then you must know clearly the level of service you are buying. There is no such thing as one size fits all. At one end of the scale, the host does just about everything for you except make you a cup of coffee. Of course, you pay for the service. At the other end of the scale, the host sold you a managed service in name only. This is what normally happens when you buy a managed server which costs hardly more than an unmanaged one. Do not expect the host to just live on fresh air and sunshine.
1. Maintenance of the hardware on which the server is running. This includes the computer components as well as peripheral equipment like connection cables, cooling systems and back-up power supply.
2. Maintenance of the software which runs the server. This includes the operating system, database software like mySql, scripting software like php and management software like cPanel.
Depending on the level of management service being paid for, support services may also include answering client enquiries, even if just to re-assure them that there are human beings looking after their server.