I hate to admit it, but the vast majority I know about, I don't know the details.
Spoiler, some classics I've read with what I can remember about them, which isn't much. I don't remember much detail about any of them.
For most of the classics I should of heard of, I probably know something about the main plot, but not much on the details. I'm more likely to get what I "know" about the classic from a movie, or a quick reference from another book.
Spoilers for classics I haven't read, major plot (from what I've heard) spoilers.
And then there are classics I know nothing about, like Daniel Deronda and East Lynne.
So, I would like to read some of these classics again (OK, not Romeo and Juliet), and read some I haven't read (Jane Eyre, it just that it is soooo looong I keep putting it off), so please use some friggin spoiler tags with classics.