It used to be only at sites where I have to give (often mandatory) PII and CC/payment information but these days I get annoyed when at least the login page of the site is not HTTPS.
Only if I'm entering credit card or other important information.
To be honest, I don't check at all, and most normal people probably don't.
I use HTTPS Everywhere so I rarely check for SSL.
You can't use HTTPS everywhere if there isn't SSL...