Mistborn: The Final Empire (it is now being marketed as YA so I guess it counts)
The Shadow of What was Lost
A Wizard of Earthsea (children's book that I read as a teenager and still enjoyed. Also, it's a fantasy classic if you are a fantasy fan as I obviously am.)
The Riddle-Master of Hed (Another classic epic fantasy series that isn't for everyone but I thoroughly enjoyed. Patrick Rothfuss also ranked it in the top 20 best books ever written if you put any stock in his opinion or know who he is. I also believe he puts Earthsea on this list. Another popular classic fantasy YA book is The Last Unicorn but I never read it as I always assumed unicorns = teenage girls, but it is apparently not that story at all.)
The Book Theif (I believe it falls into this category.)
The Giver (Another children's book that I read as a teen and still enjoyed. Much, much, much better than the book as all the weight is lessened with the older teen actors.)
The Martian Chronicles ( I was assigned it in 4th grade so I assume it's YA?)
Amazon:
Lord of the Rings (I guess this counts.)
The only really popular YA novel I remember really liking was Unwind but the follow-up books weren't great, especially the last one.
It's been years since I read any of these so they might not hold up.
Here are links to the books on amazon. I think these may be what you are looking for.