Ohhh, man. Bad question to ask. I'll try to stop myself from listing every book I've ever read, okay...
Classics: I'm not the biggest classics reader, but there are still a few I really love. First, the two best-known works of George Orwell- 1984 and Animal Farm. Animal Farm is a lot tamer than 1984, so if you were to read them, you should probably start with it. It's like a parable that's also a political critique (of Stalin to be specific.) The point he makes is excellent, and the way he crafts memorable phrases is just...wow. Like one you may have heard: "All animals are equal, but some animals are more equal than others." The last sentence is also great. It's kinda depressing, but not as much as 1984, which brings me to that. It's...really sad. But it is so good. It's one of those 'important' books. It's hard to explain, but it's just...you should read it.
Next up is A Tale of Two Cities by Charles Dickens. It's got great characters, and an even better plot. It can be a bit confusing, but the way Dickens uses symbolism is wonderful. Probably one of the few books with a well-known opening and ending sentence.
Finally, Lord of the Flies by William Golding. It really makes you think about our society and whether there's something that we're hiding. I have to say, though, reading it makes me feel like a cynic...but that's okay. He makes a valid point.
Fantasy: Ah, my favorite genre. First comes remade fairytales. Goose Girl by Patrice Kindl is good, as well as Zel by Donna Jo Napoli. Just Ella by Margaret Peterson Haddix and Ella Enchanted by Gail Carson Levine are good for the Cinderella front. Duckling Ugly and Dread Locks, both by Neal Shusterman, are not exactly remade fairytales, but they put a really dark spin on a children's story and mythology, respectively. Percy Jackson and the Olympians is another good series that puts together modern times and mythology. Moving on to general fantasy, we have Alyzon Whitestarr by Isobelle Carmody; it's got an interesting plot. Wings by Aprilynne Pike is a good spin on the old fairy story. Leven Thumps and the Gateway to Foo by Obert Skye is weird, but interesting. Erec Rex and the Dragon's Eye by Kaza Kingsley has a really interesting concept. The Xanth series by Piers Anthony is really punny. You'll be in for a long haul if you read it all, though...Piers Anthony is an excellent writer. Coraline by Neil Gaiman is awesomely creepy. The Princess Academy by Shannon Hale is good. Howl's Moving Castle by Diana Wynne Jones (not the movie, the book) is just...awesome. The characters are great. Finally, Alcatraz Versus the Evil Librarians (and the sequel) by Brandon Sanderson is funky, but good.
General Fiction: The Maximum Ride series by James Patterson (Maximum Ride: The Angel Experiment, the first one, is the best, I think) is really good and suspenseful. The Hunger Games by Suzanne Collins really makes you think about your own morals and what you would do if you had to survive. The Sea of Trolls by Nancy Farmer is good- it almost feels like historical fiction because Nancy Farmer is so good about researching the time period they're in. The Riddles of Epsilon by Christine Morton-Shaw has a good plot, pretty good mystery they have goin' on. The Giver and Gathering Blue, both by Lois Lowry, are awesome views on two different-but-similar future societies, one utopic, one dystopic, but both with problems behind them... Truancy by Isamu Fukui and Unwind by Neal Shusterman are similar books and both really good views on...well, societies that try to control everything and have ugly stuff happenin' behind the scenes.
Realistic Fiction: Jeremy Fink and the Meaning of Life by Wendy Mass is really cute, and a make-you-think book. The Anatomy of Wings by Karen Foxlee is...depressing, but so, so good. The Curious Incident of the Dog in the Night-Time by Mark Haddon is a good book about a boy with high-functioning autism trying to function in society, and also a fairly good mystery.
Okay, I hope that wasn't too many. Well, it is. I stink at giving reviews, but...*shrug* I hope I could give you some ideas, at least.