There is no way to answer that question briefly. You need to check support quality, response times. Location, network, check how much is managed and which aspects are your responsibility, etc... On the other hand, if everything is at above-average level - expect it to be expensive.
Your questions sound as if you were asking what is your favorite car is. So I will answer this. The most reliable host is the one that you are using right now. For real though could you please give is a little more info. Like what are you hosting and what kind of uptime are you looking to get.
I would add: even if server is being considered as the best for many people, that does not mean it will be best for you.
Your dedicated hosted solution should feet your needs first of all. That is the major key here. Only after your own tests you can conclude that you've got the server with feet you best.