Questions about specific hosting providers, server specs, and the suchlike are frowned upon on Server Fault, usually being closed as "too localized", or "off topic", because Server Fault isn't a good site for working out what resources you need to run a given website (because it usually requires extended discussion, is inherently subjective, and so forth).
My aim with this question is to collect a list of good sites where people who have a need to discuss the pros and cons of various hosting providers, as well as the sort of requirements they'd need for hosting a particular scale/type of site, can and visit, so that in the future Server Fault questions on those topics can be referred to this question, saving everyone a lot of grief and being as helpful as we can, within the bounds of Server Fault's remit.
For anyone who wonders why these sorts of questions aren't suitable, here are some meta questions on the subject: