So far the best hosting that I have used so far is IpServerOne (for linux,very good support, and their server is almost never down) & Hive Hosting (hive.com.my) for windows (Cheap & Reliable SQL2000 hosting),. Others which I have used:-

1) Exabytes-the worst web hosting company ever!! The company that I am working in uses Exabytes and they have been having problems everyday!! Some of the problems include:-
i) E-mail problem, once all our customers e-mail account password were reseted.

ii) Slow website loading, this happens everyday (especially in the afternoon) Sometimes the website cannot be accessed. The speed usually picks up in the middle of the night (I kid u not).

The only good thing about Exabytes is their customer support!! You can call them 24/7 and screw the kaw-kaw!! (and believe me you will)

2)Serverfreak. Not recommended. The d/l speed was very bad, many of my visitors complained, and the guy (I think his name was Sam) said that the problem was on my side!! Anyway when my hosting was about to expire he did offer to change my server (that was after a few months!), by that time I had enough and changed to a new webhosting company.