There is no best shared hosting. Anything can happen to any server or datacenter. To get close to the best, they have to have good support. So check 3 or more different hosts, go to there support, and ask them questions.
I agree with rjnsmith, ask him who has always been there to help him 24/7, he use to be a client, still is with one site, I wish him best of luck with his hosting site!
I will suggest you to try the host before making any investment. By doing this you will get to know what kind of services they offer on their servers - its speed, support etc.
2 is too low a limit, look at the huge companies, ratio of complaints to recommendationsn probaby 2:1 - But that's because people report bad news, not good.
I have hosted my site from more than one and a half years on one host. The downtime is very less, and specially the support is superb. If it is allowed here to name the host I will post here then ( any moderator please answer ).