It was the worst of lines...

The corrolary.

Opening lines to book(s) that made you question the sanity of continuing further…

So - while I can’t remember any off the top of my head - I’m sure others can.

“It was a dark and stormy night” - Snoopy

From Tim Powers’s otherwise excellent novel, Declare, comes this gem of an opening sentence:

The book gets good after the first 100 pages or so, but getting to that point, through sentences like that, was a bit of a slog.

And a whole lot of other authors, most notably Madeline L’Engle’s classic A Wrinkle in Time"

I read a lot of fan fiction (I know, I know). You know you’re in trouble when the writer can’t even bother to use proper spelling, punctuation, and/or grammar.