The first thing is reliability. The host has to be always up (I understand that it might go down every now and then but not all the time) It also has to have great support. Phone support is a must and online 24/7 is a great plus. Finally things they are offering should be within the range of their price. I hate plans where they offer 300mb space and 2 gigs of traffic for 5$ a month. That's plain ripoff.