Anne McCaffrey's Dragonflight is a classic for good reason. It starts off a little slow and the delivery is a tad rumbly in the first chapter or two, but a lot of SFF does just the same. By the fourth part (it's broken down into four parts) it's a massively entertaining ride.
The protagonist, a young lady named Lessa, is captivating. She has a strength, vitality, and stubbornness to her that makes you want to loan her an army. This story is head-hopping omniscient, so it has other characters reiterating the fact that Lessa has all of these qualities, but it doesn't even need to do so. She is written well enough that they ooze out of her like an aura. F'lar is great as a foil to her, especially because both his and her thoughts can be displayed on the same page. My favorite secondary characters are F'nor and Ramoth. Mnementh (F'lar's dragon) is pretty cool as well, although we don't get to see him developed as much as some of the others. Not a lot of stories work well in head-hopping, but this tale uses it every bit as well as the legendary Dune.
Pern is a fairly basic setting, but it has a richness in places that make it solid as a rock. It's completely unobtrusive and extremely complimentary. Certain aspects of the setting at first seem cosmetic, when they're later found to be essential in the development of the characters, world-building, and plot.
I love a certain plot thread that starts around halfway through Dragonflight. It follows the rule "for something to become an important plot point late in a story it should be foreshadowed at least three times" brilliantly. There are aspects of mystery and heist plots mixed into the "big problem" plot that make it deliciously layered and intriguing.
While this book is marketed as and considered by the late author to be sci-fi, lovers of both sci-fi and fantasy are sure to enjoy Dragonflight, especially if they like tight (not to be confused with short) narratives like Herbert's Dune and Sanderson's Elantris.