I finished Battlefield Earth.

The thing is, I remember enjoying it. I mean, it wasn't literature, but it was a lot of dumb fun.

Timequake. I love Vonnegut but I just remember it being impossible to follow and overall not interesting.

Sirens of titan. Well, Vonnegut in general. His stories are fine, probably ground breaking for the time in the sense of exploration, but the characters have no depth. It's like reading a book about npcs. Then there's the misogyny. Women are simply livestock kept around for breeding in this one, worse than an afterthought.

I don't think it's valuable to read even from a historical standpoint. Wiki synopsis would be suggested.

Z for Zachariah. I read it when I was like 15 for school. Man I remeber feeling the book is like a farming manual when they tried to survive after the nuclear war. The older man trying to rape the other 16 year old girl survivor also made me super uncomfortable. Maybe it would be better if I read it now. I just remeber it being a drag.

Alone with you in the ether. Both characters just bothered me with their weird ways of thinking. Could not relate to either of them

"Meteor" by Dan Brown (could be a different name in the original language). It was the first time I read something that was bad. Up until then book were cool and fun and interesting. It was a puzzling experience.

Edit: it's called "Deception Point" in the original.

Twilight

The Tarot of the Bohemians.

Probably not the worst I ever read, but whenever a question such as this comes up my mind immediately goes to one of the Tarot books by Piers Anthony. I don't remember which one, it was just in a pile of books people left in a dorm one time and I had nothing to read. I finished it, but I can't tell you anything about it other than the vague recollection that I hated it.