If you are interested in fantasy, there's always Lord of the Rings, or even better some of the short stories and ancillary stories that Tolkien wrote.
I would also second "Curious Incident of the Dog in the Night-Time".
Depending on how fast you read/how much time you have, "Jonathan Strange and Mr Norrell" (I might have the name slightly wrong). It's DENSE is the only thing.
Ray Bradbury's "The Martian Chronicles" are also really good. They read like short stories, so you can read it in drips and drabs, but the stories are interconnected and build together to the end. Also nice is that if you need to write a report on it for work there's a ton of great themes that can be linked to historical and current events, which makes it a good source for interesting essays and such.