There is no best, there is only the best for you. You need to seach around, make a shortlist, contact the ones on the shortlist to check out their support response times and answers. (Remember that some hosts sales@ might take longer to answer than support) And then choose the host you feel most comfortable with.
Daniel B., CEO - Bezoka.com and Ungigs.com Hosting Solutions Optimized for: WordPress • Joomla • OpenCart • Moodle Data Centers in: Chicago (US), London (UK), Sydney (AU), Sofia (BG), Pori (FI) Email Daniel directly: ceo [at] bezoka.com
Best secure reseller: www.httpme.com. Being with them for more than 2 years. Expensive, very strict but each account you place there you can go to sleep. I am at Mercury server, last 4 months 100% uptime. Support is almos instant.
Non critical accounts 1: www.gazzin.com. Cheap, fast support, short downtime.
Non critical accounts 2: www.hostndezign.com. Very fast server. About 1 downtime per month (2 or 3 hours....) Last weeks help desk started to answer very fast