To the sibling post: actually Rackspace has horrible support. They regularly experience downtime and outages and never notify customers or update their status blog. Can you get someone on the phone? Yes. Do they have anything of value to offer you? No. My favorite was when they referred me to their twitter feed, which hadn't (at the time) been posted to in 9 months.
That's not really horrible. Horrible is when AdSense shuts your account with $15k/mo revenue, confiscates $30k earnings already on the account, refuses to tell you why (a template response) and there is absolutely no human you can call and discuss this.
How does Stripe have great support? I had to wait two days for a reply. The advice I got was very good, but the response time doesn't make for "great" support.
Stripe has amazing support, even proactively reaching out when weird things happen:
Got a 500 error back from their API once and had an email from one of their engineers in my inbox almost immediately after to find out what happened and resolve it (my http lib was using stale DNS).