When it comes to web hosting, I would say the very most important thing is support and uptime. The site needs to be up all the time and if it went down then you should be able to reach someone at your web hosting provider within minutes to get your website up and working again. I would prefer to pay a little more for a web hosting that has very good uptime and support than get a cheaper hosting provider that don't have this.
I look for a webhost with the follow qualities easy to use 100% uptime 24 hr phone support reasonable price