I'm very satisfied with both <a href="https://dnsimple.com/" rel="nofollow">https://dnsimple.com/</a> and <a href="https://getssl.me/" rel="nofollow">https://getssl.me/</a><p>Very good prices, pleasant/informative websites, good buying experience. dnsimple sells certificates only if you have their dns hosting account.
I've used <a href="https://www.startssl.com" rel="nofollow">https://www.startssl.com</a> for a bunch of websites and it has been great.<p>However, I've never used any other providers so I have nothing to compare my experience to.
I buy from <a href="http://www.trustico.co.uk" rel="nofollow">http://www.trustico.co.uk</a>, they are a reseller and have used them couple of times.