The Elvenbane (Halfblood Chronicles, #1)
by Andre Norton, Mercedes Lackey
If this hadn't been a reread from when I was about 14 I don't think I would have got through it. The first 100 pages is exposition. (That's not an exaggeration, I checked. It's almost exactly 100 pages.) 80% of the text is the characters thinking for pages on end. Sometimes they arrive at suspicions and then those things are treated as facts for the rest of the story.
But my 14 year old self loved it, and that's a superpower where trashy fantasy is concerned.