How long has the host been around, it’s beneficial if they have been established for some time, but this doesn’t mean rule out the really new ones but if you are going to choose a newish hoster, ask your self how are you going to feel if your site just disappears and you have no chance of getting it back?
As for time-tested and trusted web host, can recommend
rareservers.com and their ssd vps hosting deals. Use coupon code for 25% OFF: OFFVPSTODAY
Their servers are located in USA, UK and France.
Their uptime is fantastic and ability to upgrade and downgrade is a plus.