Update 2015-10-06: Wosign decided to limit the free offer up to a point where they've no advantage over other free offers like startssl.com. They no longer offer SANs and only a validity period of 1 year. If I'm not mistaken you also have to register an account with them. Sad to see them go down that road.
I've been a proponet of CaCert.org for a long time and I'm still using those certificates in some places, but lately I gave in and searched for something that validates even on iOS. It's not that I strictly need it, it's more a favour to make life for friends and family easier.
I turned down startssl.com because I always manage to somehow lose the client certificate for the portal login. Plus I failed to generate several certificates for subdomains within the primary domain. I want to use different keys on purpose so SANs are not helpful, neither are wildcard certs for which you've to pay anyway. Another point against a wildcard cert from startssl is that I'd like to refrain from sending in my scanned papers for verification.
On a sidenote I'm also not a fan of random email address extractions from whois to sent validation codes to. I just don't see why the abuse desk of a registrar should be able to authorize on DV certificates for a domain under my control.
So I decided to pay the self proclaimed leader of the snakeoil industrie (Comodo) via cheapsslshop.com. That made 12USD for a 3 year Comodo DV certificate. Fair enough for the mailsetup I share with a few friends, and the cheapest one I could find at that time. Actually no hassle with logins or verification. It looks a bit like a scam but the payment is done via 2checkout if I remember correctly and the certificate got issued via a voucher code by Comodo directly. Drawback: credit card payment.
Now while we're all waiting for letsencrypt.org I learned about the free offer of wosign.com. The CA is issued by the StartSSL Root CA, so technically we're very close to step one. Beside of that I only had to turn off uBlock origin and the rest of the JavaScript worked fine with Iceweasel once I clicked on the validity time selection checkbox. They offer the certificate for up to 3 years, you can paste your own csr and you can add up to 100 SANs (Update 2015-08-30: Seems wosign decided to limit the SANs to 10 now. Still enough for household use I'd say). The only drawback is that it took them about 12 hours to issue the certificate and the mails look a hell lot like spam if you sent them through Spamassassin.
That provides now a free and validating certificate for sven.stormbind.net in case you'd like to check out the chain. The validation chain is even one certificate shorter then the chain for the certificate I bought from Comodo. So in case anyone else is waiting for letsencrypt to start, you might want to check wosign until Mozilla et al are ready.
From my point of view the only reason to pay one of the major CAs is for the service of running a reliable OCSP system. I also pointed that out here. It's more and more about the service you buy and no longer just money for a few ones and zeroes.