The two most important factors to consider when choosing a provider are the support and the facilities. Great customer and technical support can make or break your site hosting experience.
Expertise counts, too.
When it comes to facilities, focus on how well provisioned the service is to outlast disaster. This includes power outages, cut telecom cables, floods, and fire. Like a Timex watch, you still want your site to keep on ticking no matter the calamity. You'll also want to look into the Internet connections. Find out how many and how large a connection they have to the Internet.