As others have said:

- George RR Martin, though be prepared for sex, violence, and death.

- Rowling is among the best in YA fantasy.

- Suzanne Collins' "Hunger Games" trilogy is also great, but I don't know if that's really fantasy...seems more speculative/dystopic fiction. Unless there are some elements I'm forgetting.

- Marion Zimmer Bradley is amazing. I haven't read any of the Darkover novels yet, but she has two books that are female-centered takes on classic legends, and both are amazing - "Mists of Avalon" which is Arthurian legend from Morgan le Fay's POV, and "The Firebrand", which is "The Iliad" from Cassandra's POV.

A few others that haven't been mentioned yet:

- Jacqueline Carey: I love the religion she created for her Kushiel/Naamah series. The first trilogy is in this series is excellent - the subsquent books get a little weaker, IMO, but are still entertaining. She also wrote a duology called The Sundering which is basically Lord of the Rings from the POV of Sauron and his crew...very intriguing. It reminded me a lot of Brust's "To Reign In Hell".

- Robin Hobb has a set of eleven books that take place in the same inter-related world. To me, the best are the Liveship Traders trilogy, though the others are decent. Stay away from her unrelated Soldier's Son trilogy though...it has the most whiny, least relatable main character I've ever seen.

- Naomi Novik's Temeraire series is a little thinly written, but still fun. Basically Horatio Hornblower plus dragons.