If your looking for shared hosting then I fully reccomend Bluehost, seldomly has any downtime, they also have live chat available 24/7 whitch I have found invaluable.
I have hosting accounts with several other companys such as:
Media Temple - customer service is terrible, they rarely respond to my support questions.
Dream host - is OK. dont like there custom control panel
Site 5 - they seem to reboot servers on a weekly basis (that's how it appears for me atleast) as my sites go down around once a week for 15+ mins, customer service is OK, there friendly and always respond to emails but waiting time varys from 2 mins to 8+ hours.
Cirtex Hosting - OK for small sites, but if you use alot of CPU resources they will suspend your account pretty quickly.
Thats my round up of shared hosts from personal experiences